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A Venturedyne, Ltd., Company

WinVCS 2

Instruction Manual

Revision 13: July 31, 2017

This generic manual is intended for reference purposes only and is not intended to

be used to operate your equipment. For operating instructions and a description of

the features used on your specific control system, see the manual set supplied with

your Thermotron product.

This manual provides the most current generic operating instructions for this

controller at the time of its revision date. Therefore this manual may not include

some recent software changes. This manual also may cover features that are not

available on your current controller. Examples within this manual are for typical

configurations that may not apply to the configuration of your control system.

This generic manual is not intended to be used to operate your equipment.

For additional manuals, contact Thermotron Industries:

Web www.thermotron.com

E-mail [email protected]

Phone Main 616-392-1491

Product Support 616-392-6550

Marketing 616-393-4580

Fax Product Support 616-393-4549

Marketing 616-392-5643

Address 291 Kollen Park Drive

Holland MI 49423

USA

Thermotron Industries

The information in this document is subject to change without notice. No part of this document

may be reproduced or transmitted in any form or by any means, electronic or mechanical,

without the express written permission of Thermotron Industries. Thermotron Industries may

have patents or pending patent applications, trademarks, copyrights, or other intellectual

property rights covering subject matter in this document. The furnishing of this document does

not give you license to these patents, trademarks, copyrights, or other intellectual property

except as expressly provided in any written license agreement from Thermotron Industries.

All relevant issues have been considered in the preparation of this document. Should you notice

an omission or any questionable item in this document, please feel free to contact the

Thermotron Product Support group between 8:00 AM and 4:30 PM Eastern Standard Time at

616-392-6550.

Regardless of the above statements, Thermotron Industries assumes no responsibility for any

errors that may appear in this document, nor for results obtained by the user as a result of using

this product.

Destination Control: These commodities, technology or software when exported from the

United States or re-exported, are subject to Export Administration Regulations (EAR). Diversion

contrary to U.S. law is prohibited.

Revision 13: July 31, 2017

WinVCS 2 Instruction Manual Table of Contents/Specifications

Thermotron Industries This generic manual is not intended to be used to operate your equipment. i

Table of Contents Specifications .................................................................................................................................................... iii

Section 1: Operating WinVCS 2 .................................................................................................................... 1-1

Overview of the VCS system ......................................................................................................................................................................... 1-1

Introduction to WinVCS 2 .............................................................................................................................................................................. 1-2

Loading and exiting WinVCS 2 .................................................................................................................................................................... 1-2

Creating a new test ........................................................................................................................................................................................... 1-3

Loading an existing test .................................................................................................................................................................................. 1-3

The menu bar ...................................................................................................................................................................................................... 1-4

The toolbar ........................................................................................................................................................................................................... 1-7

The amplifier control bar ................................................................................................................................................................................ 1-8

The control panel ........................................................................................................................................................................................... 1-10

Mode status panels ....................................................................................................................................................................................... 1-11

Event log ............................................................................................................................................................................................................ 1-12

Multiple cursors............................................................................................................................................................................................... 1-13

Graph and data functions ........................................................................................................................................................................... 1-18

Report generation .......................................................................................................................................................................................... 1-22

Accessing the test options.......................................................................................................................................................................... 1-25

Safety parameters function ........................................................................................................................................................................ 1-26

Power savings .................................................................................................................................................................................................. 1-28

Running a test .................................................................................................................................................................................................. 1-30

Assigning and running a test schedule ................................................................................................................................................. 1-31

Disable blower function ............................................................................................................................................................................... 1-32

Abort messages ............................................................................................................................................................................................... 1-33

Section 2: Random Mode ............................................................................................................................... 2-1

Random mode graphs..................................................................................................................................................................................... 2-1

Defining a new random test ......................................................................................................................................................................... 2-4

Using a model or resume drive ................................................................................................................................................................ 2-12

Editing an existing test ................................................................................................................................................................................. 2-13

Sine on random mode (optional) ............................................................................................................................................................ 2-14

Random on random mode (optional).................................................................................................................................................... 2-17

Shaker limits in random mode.................................................................................................................................................................. 2-19

Section 3: Sine Mode ...................................................................................................................................... 3-1

Sine mode graphs ............................................................................................................................................................................................. 3-1

Types of sine testing ........................................................................................................................................................................................ 3-3

Defining a new sweep test ............................................................................................................................................................................ 3-3

Defining a new fixed frequency or search and dwell test ............................................................................................................. 3-10

Editing an existing test ................................................................................................................................................................................. 3-14

Table of Contents/Specifications WinVCS 2 Instruction Manual

ii This generic manual is not intended to be used to operate your equipment. Thermotron Industries

Graphing an armature response plot ..................................................................................................................................................... 3-14

Swept sine step change tests .................................................................................................................................................................... 3-16

Resonance search and dwell tests ........................................................................................................................................................... 3-19

Finding the resonance frequencies by touch ..................................................................................................................................... 3-22

Defining swept sine dwelling .................................................................................................................................................................... 3-22

Shaker limits in sine mode.......................................................................................................................................................................... 3-23

Section 4: Shock Mode ................................................................................................................................... 4-1

Shock mode graphs.......................................................................................................................................................................................... 4-1

Defining a new shock test .............................................................................................................................................................................. 4-3

Editing an existing test .................................................................................................................................................................................... 4-7

Shock response spectrum (optional)......................................................................................................................................................... 4-8

Pre- and post-pulse compensation options ....................................................................................................................................... 4-11

Adaptive pre- and post-pulse compensation .................................................................................................................................... 4-13

Shock pulse reference filter options ....................................................................................................................................................... 4-13

Shaker limits in shock mode ...................................................................................................................................................................... 4-16

Section 5: RealData Mode ............................................................................................................................. 5-1

RealData graphs ................................................................................................................................................................................................. 5-1

Recording data ................................................................................................................................................................................................... 5-3

Configuring a RealData test .......................................................................................................................................................................... 5-5

Section 6: Technical Displays and Computer Interface Commands ...................................................... 6-1

System Options panel ..................................................................................................................................................................................... 6-1

Calibration menu commands ....................................................................................................................................................................... 6-3

Using the TCP/IP or GPIB computer interface ....................................................................................................................................... 6-6

Using the command set.................................................................................................................................................................................. 6-6

Using the WinVCS 2 web server .................................................................................................................................................................. 6-8

Section 7: VCS Electronic Interface .............................................................................................................. 7-1

Installing the hardware ................................................................................................................................................................................... 7-1

Calling Thermotron for technical support............................................................................................................................................... 7-2

Appendix A: Specific Mode Features and Capabilities ............................................................................. A-1

Random mode ................................................................................................................................................................................................... A-1

Sine mode ............................................................................................................................................................................................................ A-2

Shock mode ........................................................................................................................................................................................................ A-3

RealData mode .................................................................................................................................................................................................. A-3

Appendix B: Definition of Terms ................................................................................................................. B-1

Common terms................................................................................................................................................................................................... B-1

Special definitions ............................................................................................................................................................................................. B-3

Formulas ................................................................................................................................................................................................................ B-5

WinVCS 2 Instruction Manual Table of Contents/Specifications

Thermotron Industries This generic manual is not intended to be used to operate your equipment. iii

Specifications NOTE: See Appendix A for additional information on random, sine, shock, and/or RealData modes.

Minimum PC requirements

Operating system required Microsoft Windows 7

Microprocessor 2.4 GHz minimum, dual or quad core recommended

Random access memory 1 GB RAM minimum, 2 GB RAM recommended

Video 15-inch SVGA monitor (1024 x 768 minimum resolution)

Available hard drive space 40 GB or greater

Ports One USB (for the printer)

Miscellaneous

Test scheduling Sine, shock, random, and RealData tests can be scheduled.

Transducer sensitivity scaling User programmed to desired level.

Each input has calibration factor for calibrated accelerometers.

Range of 1 to 1,000 mV/g (1 to 102 mV/m/s2).

Table of Contents/Specifications WinVCS 2 Instruction Manual

iv This generic manual is not intended to be used to operate your equipment. Thermotron Industries

WinVCS 2 Instruction Manual Operating WinVCS 2

Thermotron Industries This generic manual is not intended to be used to operate your equipment. 1-1

Section 1: Operating WinVCS 2

Overview of the VCS system

The VCS is a microcomputer-based system used to control, monitor, and acquire data from an electrodynamic shaker.

The VCS integrates random, sine, shock, RealData, and other optional modes of vibration control. The VCS consists of

a PC running Windows and the WinVCS 2 software package, a DAQ card, and a vibration I/O module (VIO).

The VCS provides the following functions and features:

• Provides programmability and profile display through Windows-style software screens.

• Applies a programmed drive signal to a shaker to execute vibration tests on a product.

• Inputs multiple accelerometer signals to interpret the response of the shaker or product.

• Corrects the drive signal to compensate for changes caused by the mechanical characteristics of the shaker or

product.

• Produces a response from the product that conforms, within predetermined limits, to the content of a test

standard.

• Produces outputs that permit annotated recording of response plots.

VCS system electronic interface

NOTE: The following is a general overview of the vibration control system’s electronic interface. For more detailed

information, refer to the instrument wiring and other schematics included with your shaker documentation.

The VCS controls the vibration system using a personal computer, vibration I/O (VIO) module, and accelerometers.

1. Each accelerometer develops a variable signal based on its sensitivity and the acceleration produced by the

shaker.

2. The VIO module routes the accelerometer signal to the PC’s data acquisition (DAQ) card.

3. The control algorithm in WinVCS 2 adjusts the amplifier drive signal until the accelerometer signal reaches the set

point.

4. The amplifier drive signal is sent from the PC’s DAQ card to the VIO module. The full scale value of the drive

signal is ±10 volts.

5. The VIO module sends the amplifier drive signal to the amplifier’s machine controller.

6. The machine controller converts the amplifier drive signal into a throttle for the inverter(s).

7. The inverter(s) provide the shaker armature current.

8. The amplifier parameters can be set through the optional amplifier communication cables.

Operating WinVCS 2 WinVCS 2 Instruction Manual

1-2 This generic manual is not intended to be used to operate your equipment. Thermotron Industries

Introduction to WinVCS 2

WinVCS 2 provides frequency-domain test definitions and displays for random, sine, shock, and RealData testing. The

software works with the NI-DAQ card to convert time-domain inputs from the shaker into frequency-domain data.

The conversions are performed using the fast Fourier transform model. The software also converts the frequency-

domain drive profile into a time-domain drive signal sent to the NI-DAQ card.

The vibration control system provides closed-loop programming and control for local shaker operations as well as

remote shaker operations. See Section 7 for the installation procedure.

Installation information

The vibration control system PC ships from the factory with all of the necessary software installed. If you need to re-

install any of the software please call the Thermotron Product Support group at (616) 392-6550.

Loading and exiting WinVCS 2

CAUTION: Set the shaker amplifier to a gain of zero when you start the software. Once the software loads, set

the amplifier’s gain to the desired level. (Newer versions of the WinVCS software handle this automatically.)

1. Make sure the entire vibration control system is fully installed according to the procedures in Section 7.

2. Power-up or reset the PC.

3. Double-click on the WinVCS 2 desktop icon to run the software.

4. To exit the software, select Exit from the File drop-down menu.



Creating a new test

1. Select the desired mode by selecting Random, Sine, Shock, or RealData from

the Options/Mode drop-down menu, or by clicking the desired mode icon on

the toolbar.

NOTE: Sine on random and random on random are selected from the Random Control System Properties

panel. See “Sine on random mode (optional)” and “Random on random mode (optional)” in Section 2 of this

manual.

2. To create a new test

• Select New Test from the File drop-down menu, or

• Click the New Test icon on the toolbar, or

• Press Ctrl+N.

3. The test definition wizard for the selected mode loads. See the appropriate sections later in this manual to define

a specific test.

Loading an existing test

1. To open an existing test:

• Select Open Existing Test from the File drop-down menu, or

• Click the Open Existing Test icon on the toolbar, or

• Press Ctrl+O.

2. The Open dialog box

displays the available tests.

3. Select the desired test from

the default folder or browse

to another location.

NOTE: All tests have the

*.vcs file extension.

4. To load the selected test,

press the Open button.

NOTE: When a test is loaded,

the mode is automatically

selected from the test

definition.

5. To close the Open dialog

box without loading a test,

press the Cancel button.



The menu bar

The menu bar contains ten drop-down menus that provide access to all commands and functions. In addition, many

of the commands have toolbar buttons, control panel buttons, and hot keys.

File menu commands

New Test (Ctrl+N) Opens the test definition wizard for the currently selected mode. Use this command

to define a new vibration test. Once a test is defined it is automatically loaded.

Open Existing Test (Ctrl+O) Opens a pre-existing test from the default directory.

Save Test (Ctrl+S) Saves the currently loaded test in the default directory.

Save As Saves the currently loaded test with a user-selected name and location.

Print (Ctrl+P) Sends the currently selected graph layout to the printer.

Print Preview Displays how the currently selected graph layout will appear when printed.

Print Test Definition Sends a report of the currently loaded test’s defined options to the printer.

Exit Exits the software.

Edit menu commands

Undo (Ctrl+Z) Undoes the last change.

Cut (Ctrl+X) [Command not available.]

Copy (Ctrl+C) Copies the currently selected graph to the clipboard.

Paste (Ctrl+V) Pastes data from the clipboard.

View menu commands

Toolbar Displays the toolbar. The toolbar allows you to access various functions without using

the drop-down menus. See “The toolbar” later in this section.

Control Panel Displays the control panel, which displays the operation buttons and lamps. See “The

control panel” later in this section.

Status Panel Displays the status panel. The status panel displays the active accelerometer and the

real-time parameters as well as the operational status, the last start time of the active

test, and the current level of the test. See “Mode status panels” later in this section.

Cursor Panel Displays the cursor panel, which provides access to multiple cursor options. See

“Multiple cursors” later in this section.

Status Bar Displays the status bar at the bottom of the main window. The status bar displays the

current status of the software.

Graph buttons Allows you to select the different graphic layouts on the main window. You can

display up to four graphs in a combined layout. NOTE: Use Ctrl plus a specific value

(1-4) to display a specific number of graphs. For example, Ctrl+4 will display four

graphs.

Event Log commands

View Event Log Allows you to view the event log as a rich text (*.rtf) document.

Add Note Opens a dialog box and allows you to add a comment to the event log.

Clear Event Log Clears the event log.



Explore Old Logs Opens Windows Explorer and allows you to browse old log files.

Log Seconds Check this option to log and display events in the event log down to seconds.

Graph menu commands

Graph Each mode has its own graph selections. When you

open the drop-down menu, there is a check mark next

to the displayed graph type (for example, Control

Response) of the selected graph. To select a different

graph type for the selected graph, click on the desired

graph type.

Show Limits Turns the tolerance and abort limit lines on or off for

all affected graph displays.

Line Graph Turns the line connections on or off for all graphs.

With the lines turned off, the graph shows the points

of resolution where the A/D converters read the

responses. With the lines turned on, the graph

connects the dots, showing the graph in line format.

Setup Opens the graphing properties panel for the current mode. Use this panel to adjust

the graphic displays and to set up the auto-save or auto-copy options.

Next View Changes the view on the selected graph area to the next graph on the list.

Options menu commands

Test Setup Opens the System Properties panel for the current mode. The System Properties

panels display all of the fields and tables needed to define a test in the current mode.

System Options Opens the System Options panel. This panel allows you to set up the general

options, TCP server options, line colors (for graphs), web server options, and amplifier

control options.

Digital I/O Opens the Digital I/O dialog box.

Manual Mode This option is available when running fixed sine tests, and it allows the user to adjust

the frequency of the tone as well as the amplitude by ±6dB.

Schedule Tests Opens the Test Schedule panel. The Test Schedule panel is used for assigning and

running multiple tests. It also provides access to the Remote Schedule Index panel,

which allows you to assign up to seven test schedules for remote selection.

Mode Provides the mode selections. Sine, Shock, Random, or RealData can be selected.

The mode selection sets up the displays and commands for the current test. NOTE:

Sine on random and random on random are selected from the Random Control

System Properties panel.

Fixed Output Drive In sine mode Fixed Output Drive is used to get the spectral response of the shaker

system. When this option is enabled, the controller will bring the test up to the

desired G level, then hold it there. When the Run button is pressed, the controller

locks the output drive at whatever it equalized to, and keeps the same drive for an

entire up and down sweep of the spectrum. This results in an acceleration plot that

shows the response of the shaker system. Thermotron runs this test on every shaker

that ships from the factory so we have a reference. It is useful for finding problems

with the shaker in the field, as another sweep response test can be run and checked

against the reference for changes.



Command menu commands

Run (Ctrl+R) Places a test in run mode from stop mode or hold mode:

• From stop mode, run mode starts the test at Level 1. It first checks the response

of a small test signal for a minimum start voltage (random is in Vrms, sine is in

Vpk, and shock is in mV). Once it detects the response, the system starts up

according to the start mode on the level schedule.

• From hold mode, run mode resumes the test at the current drive and allows the

test clock to continue counting.

Stop (Ctrl+T) Places a test in stop mode and ends the test.

Resume Continues a test in hold mode at the current drive and allows the test clock to

continue counting.

Hold Suspends a test, causing the WinVCS 2 software to output a fixed drive signal and

stop the test clock. Hold mode also suspends tolerance and abort limit checking. The

Run State lamp flashes yellow while the test is in hold mode.

Read Inputs In RealData mode, select this command to begin recording data.

Next Level Advances a test to the next level defined on the level schedule. The WinVCS 2

software starts the next level based on the level’s defined start mode. This command

is disabled when the test reaches the last level.

Previous Level Returns a test to the previous level in the defined level schedule. The WinVCS 2

software starts the previous level based on the level’s defined start mode. This

command is disabled when the test is at the first level.

System Status Displays the monitor and control inputs’ current sensitivity, calibration factors, control

gain, and monitor gain settings.

Data & Reports menu commands

Save Drive Random mode function that saves the drive during a test as a model start on the

defined level schedule.

Clear Stored Drives Random mode function used to clear the drives stored as model starts or resume

starts on the defined level schedule.

Save Current Data Saves the data from the current test to a file. The software saves the data under the

test name, followed by a three-digit file extension that increases each time you save

the data (for example, Sweep.000, Sweep.001, Sweep.002, etc.).

View Saved Data Allows you to load and view the data saved using the Save Current Data command.

Generate Report Allows you to save a report at any time while a test is running.

Report Generation Setup Opens the Report Generation and Data Setup dialog box.

Calibration menu commands

Edit Accel Sensitivity Opens the Edit Accelerometer Sensitivity panel. This panel allows you to enter the

certified sensitivity of the accelerometer attached to each input channel.

Live Calibration Opens the Live Calibration panel. This panel allows you to check the response of the

closed loop system, consisting of the vibration control system, shaker, and one

accelerometer channel at a time.

Input Verification Opens the Input Verification panel. This panel allows you to test the accuracy of the

I/O module’s input channels.



Help menu commands

Help Topics Opens the online help, which allows you to find information about various topics and

functions.

Update Registration Opens the Update Registration panel.

About WinVCS Opens the About WinVCS

panel shown here. This panel

indicates which options are

enabled. To close this panel,

press the OK button.

The toolbar

The toolbar contains icons that provide access to commands and functions. In addition, many of the commands have

menu bar or control panel buttons. The toolbar icons from left to right are:

New Test (Ctrl+N) Opens the test definition wizard for the currently selected mode. Use this command

to define a new test. Once a test is defined, it is loaded.

Open Existing Test (Ctrl+O) Opens an existing test from the default directory.

Save (Ctrl+S) Saves the currently loaded test in the default directory.

Copy (Ctrl+C) Copies the currently selected graph to the clipboard. To select a graph, click on the

graph in the main window.

Print (Ctrl+P) Opens the Print panel.

Vibration Modes Selects the mode for the current test (Random, Sine, Shock, or RealData). NOTE:

Sine on random and random on random are selected from the Random Control

System Properties panel.

System Options Opens the System Options panel. This panel allows you to set up the general

options, TCP server options, line colors (for graphs), web server options, and amplifier

control options.

Graph Setup Opens the graphing properties panel for the currently selected graph. Use this panel

to adjust the graphic displays and to set up the auto-save or auto-copy options.

Next View Changes the view of the selected graph area to the next graph on the list.

Graph Buttons Selects the number of graphs to display on the main window (1-4). NOTE: Press Ctrl

plus a specific value (1-4) to display a specific number of graphs. For example, Ctrl+4

will display four graphs.

Next Level Advances a test to the next level defined on the level schedule. The WinVCS 2

software starts the next level based on the level’s defined start mode. This command

is disabled when the test reaches the last level.



Previous Level Returns a test to the previous level in the defined level schedule. The WinVCS 2

software starts the previous level based on the level’s defined start mode. This

command is disabled when the test is at the first level.

Disable Blower Disables the blower for low noise operation. For more information, see “Disable

blower function” later in this section.

Read Inputs In RealData mode, press this button to begin recording data.

Manual Sine Mode This option, available when running fixed sine tests, allows the user to adjust the

frequency of the tone as well as the amplitude by ±6dB.

Help Topics Opens the online help for information on various topics and functions.

The amplifier control bar

The above illustration shows the amplifier control bar, which indicates that the amplifier communication is not

working. For amplifier communication to operate, the shaker hardware and the controller hardware must be

connected appropriately. Notice the question mark in the status icon and the No Comm message next to it.

If you have enabled amplifier communication, the amplifier control toolbar is displayed beneath the standard toolbar.

The amplifier control bar allows you to control Thermotron’s amplifier from the WinVCS 2 software. The amplifier

control bar is divided into two sections: the amplifier controls and the specification information.

Status The status icon indicates whether the amplifier is started (green) or stopped (red) and

if communication has been established between the software and the amplifier. The

status light also doubles as an active icon to allow you to start the shaker amplifier

without starting the current active test. To do so, right-click the mouse over that icon

when it shows a stopped condition and follow the pop-up box instructions. This

method is very useful for diagnosing the amplifier.

Amplifier output indicator Indicates the current output of the amplifier.

Amplifier adjust field Allows you to tweak the amplifier control for peak performance.

Access level menu The access level drop-down menu allows you to view different pages in the amplifier

adjust field. You can select lock, basic, advanced, or factory. The basic and advanced

pages are described below. For additional information, see “Appendix A: Calibrating

the EDV System” in the EDV Console Instruction Manual.

Basic display pages

These pages are used for normal operation.

Gain Displays the amplifier gain as a percentage of full output. You can adjust the gain up

or down using the value switch. Normally, the gain is left at 100% output to allow the

vibration controller to control the full range of output to the armature.

Armature Current Displays the armature current in true RMS amp. Use the value switch to display the

Armature Limit setting.



Field Adjust This appears only if your shaker is configured for an adjustable field. It displays the

adjustable field current in amps DC. You can adjust the field’s current output up or

down using the value switch. The range of the variable field is 0 to 255 amps.

If an output that is greater than the range of the system is selected, the actual field

current is set as high as possible and runs uncontrolled. The factory default maximum

field trips at its original setting. The low current trip automatically adjusts to 1/8 of the

set point current, or is set to zero if the set point is below five amps. For additional

information, see “Using the Field Adjust Page to Set Up the Variable Field Supply” in

the EDV Console Instruction Manual.

Field Displays the field current in amps DC. Press the value switch up to display the Field Hi

Limit setting or down to display the Field Low Limit setting.

Run Time Displays the shaker system’s run time in hours.

Blower On/Blower Off Displays the blower’s on/off status and how long in minutes the blower will remain in

that state. An XX indicates the blower will remain in the displayed state.

Gain Recall Provides a gain recall selection. Use the value switch to select Yes or No. Select Yes to

recall the last system gain and No to start the gain at zero. Note that you must always

select Yes to operate in the remote mode. The No selection is only convenient in the

local mode for system testing.

Center Displays the centering mode for the dynamic centering system (DCS). Use the value

switch to select the STD or LOW centering mode.

• STD centers the armature in the center of its peak-peak travel range.

• LOW centers the armature approximately half way between the standard center

of travel and the low range of travel. This allows shock tests with simple pre- and

post-pulse compensation to be programmed with greater displacements.

Advanced display pages

These pages allow you to monitor the system and set some system operational parameters.

Shaker Temp Displays the shaker outlet air temperature in degrees Celsius. Press the value switch to

display the High Temp Limit setting.

Vacuum Displays the vacuum pressure dropped by the shaker in inches of water. Use this value

to make sure the blower is operating properly. Press the value switch to display the

Vacuum Low setting.

Amplifier Temp Displays the heat sink temperature in degrees Celsius at the amplifier bridge. This

reading indicates how hot the amplifier power supply is. Press the value switch to

display the Amp Temp Limit setting.

Field Temp Displays the heat sink temperature in degrees Celsius at the field coils’ semi-

conductor bridge. This reading indicates how hot the field power supply is. Press the

value switch to display the Field Temp Limit setting.

Alarm Provides an audible fault alarm selection. Use the value switch to select Yes or No.

Select Yes to enable the audible alarm when the machine controller detects a fault.

The alarm can be silenced by pressing the STOP button. Select No to disable the

audible alarm.

Auto Reset Provides a reset-on-fault selection. Use the value switch to select Yes or No. Select

Yes to enable the Auto Reset function to attempt to reset and start the shaker when a

fault occurs. If the Auto Reset function fails to restart the shaker, the machine

controller stops the shaker and the control panel indicates the fault condition. Select

No to disable the Auto Reset function.



Blower Provides a means to set up the timing for the shaker blower. The page can be set to

AUTO, TIME, or TEMP. Press the value switch to change these settings.

• AUTO allows the machine controller to determine when to turn the blower on or

off during and after a test. The machine controller uses the temperature and

current readings to estimate the temperature of the shaker and operates the

blower long enough to keep the shaker temperature within its limits.

• TIME and TEMP set the time or shaker air temperature set point that must be

reached, once the shaker stops, before the blower will stop. This allows the

blower to continue to cool the shaker body. The selectable scale is 01 to 30

minutes, and from 20 to 60 degrees Celsius.

Aux Out Sets the TTL AUX OUT signal to a one-second pulsed (PL) output or a level (LV)

output. This has no function without the optional (deprecated) control panel.

Start Out Sets the rear panel START OUT signal to a one-second pulsed (PL) output or a level

(LV). The start output becomes active once the shaker has finished its start sequence.

This has no function without the optional (deprecated) control panel.

Stop Out Sets the rear panel STOP OUT signal port to a one-second pulsed (PL) output or a

level (LV). The stop output becomes active once the shaker is stopped. This has no

function without the optional (deprecated) control panel.

DCS Set This setting allows you to check the DCS sensors. Use the value switch to select Yes or

No. Select Yes to enable manual adjustment of the DCS, and select No to maintain

automatic adjustment of the DCS. For addition information, see “Checking the DCS

Sensors” in the EDV Console Instruction Manual.

The control panel

The control panel contains the operation buttons that allow you to operate the system as well as the status lamps that

display the current status of the system.

Operation buttons and status lamps

• To resume a paused test, press the Resume button.

• To pause a test, press the Hold button.

• To access the System Properties panels for the current mode, press the

Test Setup button.

• To begin a test, press the Run button.

• To stop a test, press the Stop button.

• The Run State lamp turns green when the software is operating the shaker.

When a test begins, the lamp flashes until the drive and control response

signals stabilize. When a test is in hold mode, the lamp flashes yellow until

the test is resumed or stopped.

• The Warning lamp turns yellow whenever the response plot crosses the tolerance limits

(inner limits).

• The Abort lamp turns red when a test aborts for any reason.



Input channel status

Displays the current reading for all control and monitor accelerometers.

• Control accelerometers are indicated by the green CTRL light.

• Monitor accelerometers are indicated by the green MON light.

• A red light indicates a problem with a defined accelerometer.

• Undefined accelerometer channels are black.

The power setting mode indicator is located above the input channel status. For

more information on the power setting mode indicator, refer to “Power savings”

later in this section.

Mode status panels

The status panel for each mode displays real-time accelerometer readings and test settings. For more information,

refer to the appropriate mode sections later in this manual.

Random mode status

The status panel displays the following parameters during a random mode test:

• Control (G RMS): Averaged control channel accelerometer readings. Only

the response within the defined control range is included.

• Drive (V RMS): The drive signal output.

• Target (G RMS): The reference profile’s acceleration set point.

• Max Freq (Hz) : The maximum frequency of the current test.

• Lines: The number of lines of the current test.

• Bandwidth (Hz): The result of the maximum frequency divided by the number of lines in the current test.

Sine mode status

The status panel displays the following parameters during a sine mode test:

• Accel. (G): The accelerometer readings in the current segment’s scale.

• Reference (G): The reference profile’s set point in the current segment’s

scale.

• Velocity (in/s): The current velocity of the armature.

• Freq (Hz): The current frequency of the test.

• Disp. (in): The current displacement of the armature.

• Drive (V): The drive signal output.

NOTE: When a test is running, the current control value is displayed in yellow.



Shock mode status

The status panel displays the following parameters during a shock mode test:

• Peak (G): The acceleration peak of the most recent pulse.

• Peak Ref (G): The peak acceleration set point.

• Max Drive (V): The voltage peak of the most recent drive signal.

• Vel Ref (in/s): The maximum reference velocity of the test.

• Width (ms): The pulse width.

• Disp Ref (in): The maximum reference displacement of the test.

RealData mode status

The status panel displays the following parameters during a RealData mode test:

• Control (G RMS): Control channel accelerometer readings.

• Drive (V RMS): The drive signal output.

• Target (G RMS): The current set point.

• Error: The percentage of error in reproducing the real test data.

• Max Freq (Hz): The maximum frequency of the current test.

• Source Rate: The sample rate of the RealData file recording.

Event log

The event log displays:

• The current Level of the test and number of test levels

• The Elapsed/Total time of the test

• The Start Time and date of the test

• The most recently recorded events

• Press the Note button to open the

Add Event Log Comment dialog box,

which allows you to add a comment to

the event log.

• Press the View button to view the

event log as a rich text (*.rtf) file.

• Press the Clear button to clear the

event log.



Multiple cursors

The cursor panel provides access to the multiple cursor feature. The multiple

cursor feature includes the following functions:

• Add up to 12 cursors on a graph

• Display dB levels

• Snap to peak and notch

• Mirror cursors across all graphs

• Peak and notch detection

• Rename channels

Each function is described below.

Scale X and Scale Y check boxes

The cursor panel check boxes for Scale X and Scale Y activate continuous auto-scaling for the selected graph.

Manually setting a limit disables the appropriate auto-scaling. Auto-scaling is suspended on zoomed-in graphs.



Adding multiple cursors to a graph

The cursor panel on the left shows the selected cursor and cursor options for the active graph. To add additional

cursors, select the desired cursor from the drop-down menu on the left and click on the graph.

• When only one or no cursors are active on the graph, the graph is the same size as before and the cursor appears

as it used to: a line with a flag showing the point it intersects with on the graph.

• When two or more cursors are active, the cursor changes to a “V” pointing to the top channel and an “X” over the

point on any additional channels labeled by the cursor number. A color-coded table is also drawn on the right.

The table is also displayed when printing the graphs and generating a report.

If you want to move another cursor that is already on the screen, instead of selecting the cursor from the drop down

menu, you can click on the cursor to activate that one.

The Clear cursor button can be used to clear all the cursors at once instead of having to select and remove each

cursor individually.



dB levels

If two or more cursors are displayed on the graph, the dBs from the highest cursor are displayed in the cursor table.

The dB level is calculated as where is amplitude for each cursor and is the

greatest cursor amplitude. The dB levels are calculated for each channel. If the y-axis is not logarithmic, the dB level

will not be shown.

Mirror cursors

Mirroring Cursors causes the cursors to be placed at the same x-position on all the graphs. Cursor tables will also be

aligned and dB levels will be shown on all graphs if enabled. Cursors are only mirrored on graphs with the same

x-axis; cursors from a graph of the frequency will not be displayed on a graph of time. The table length will be

mirrored.



Snap to peak/notch

Snap to peak and snap to notch cause the cursor to jump to the peak/notch closest to the click if one is nearby.

Peak and notch detection

Selecting the Peak button in the top dialog bar will bring up the Peak

Detection dialog box, which allows you to choose the parameters for the

peak search.

• Under Detection type select Peak or Notch. If you enable Baseline

(explained below), both peaks and notches can be searched for at the

same time.

• The Number of peaks/notches searched for can be changed, but must

be no more than 12, which is the maximum number of cursors a user

can place. If fewer than the specified number of peaks/notches are

detected, those that were detected will be displayed and the rest of the

cursors will be hidden.

• Peak/notch sharpness refers to the dBs above the point for peaks, or

below the point for notches. Increasing the parameter will cause it to

look only at sharper peaks, while decreasing it will include rounder

peaks in its search.

• If too many peaks are right next to each other, the Minimum space between peaks/notches can be increased

so that two peaks must be at least that far apart before the shorter one will be included.

• If Baseline is enabled, it will only search for peaks or notches outside of the specified range around the baseline.

The range is in dBs.

Peaks are sorted by height and notches are sorted by depth. If Baseline is enabled, peaks/notches are sorted by the

absolute value of the log of their distance from the baseline.



Customizing the cursor colors and channel names

The color for each cursor can be changed from

the Graphing Properties dialog box. The

channels can also be renamed with names up to

five characters long.



Graph and data functions

The graphic displays are interactive charts for the different signal measurements. The graphic displays can be adjusted

to show up to four graphs. The scales and properties of each graph can also be adjusted. Each mode has its own set

of graphs that are described in more detail in the specific mode section of this manual.

Viewing the graphs

1. Select the desired number of graphs to display on the main window from the

graph icons on the toolbar, from the View drop-down menu, or by using one of

the following key combinations:

• Crtl+1 to display a single large graph in the graph area.

• Crtl+2 to display two horizontally tiled graphs.

• Crtl+3 to display three horizontally tiled graphs.

• Crtl+4 to display four graphs as quadrants of the graph area.

2. Left-click on an active graph to display a

vertical line on the graph. The coordinate

where the vertical line crosses the graphed

data is displayed. To remove the line, click on

the frame of the graph window (where the

labels are). Additional cursors can be placed by

selecting a number from the Selected Cursor

drop-down menu in the cursor panel. Cursors

can be made to find the highest or lowest

nearby points by selecting Snap to peak or

Snap to notch. The Mirror Cursors check box

will cause the selected cursor to appear on all

graphs with the same abscissa (x-axis) as the

selected graph.

Tip: To zoom in on a specific area, hold the

Shift key while clicking and dragging a

rectangle in the graph window. To return to the

normal display, click the Zoom Out button.

The cursor panel check boxes for Scale X and

Scale Y activate continuous auto-scaling for

the selected graph. Manually setting a limit

disables the appropriate auto-scaling. Auto-

scaling is suspended on zoomed-in graphs.



3. Right-click on the graph to view the graph drop-down menu for the current

vibration mode. Check marks indicate the currently displayed graph and

options. The graph drop-down menu allows you to:

a. Change the displayed graph.

b. Show the tolerance and abort limits.

c. Enable or disable the line connection on the plot.

i) With Line Graph enabled, the plot connects the dots to provide a line

graph.

ii) With Line Graph disabled, the plot is displayed as separate points

according to the filter resolution.

d. Copy a graph to the Windows clipboard.

e. Save the graph as an image (*.jpeg) file.

f. Access the Graphing Properties panels for the current vibration mode.

Graph setup

1. To access the graph setup, select Setup from the Graph

drop-down menu, or right-click on the active graph and

select Setup from the drop-down graph menu, then

select the Graph Setup tab.

2. Select the desired graph from the Select Graph drop-

down menu. NOTE: Different modes allow you to select

different graphs to display.

3. Set up the X Axis and Y Axis:

a. To keep the X axis setting the same for all graphs,

check the Synchronize All X Axes check box.

b. For each axis select the scale to use, either

logarithmic (Log) or Linear.

c. Enter the Minimum and Maximum limits for each

axis.

4. Under Cursor Colors select the colors for use with

multiple cursors.

5. Under Graph Colors, select the display color for each

channel from its drop-down list.

a. To use the same colors in all graphs, check the

Synchronize All Graph Colors check box.

b. Select the graph colors from the drop-down lists.

NOTE: The Drive, Phase Angle, and Reference graphs have a Plot Line drop-down menu instead of a Control

drop-down menu. The Control Response and Monitor Response graphs have an additional check box to

activate a Reference line.

6. Under Line Colors you can modify the Tolerance and Abort colors and the Cursor Cross setting. The check box

allows you to Enable warning highlights.

7. The colors of up to 16 channels can be selected under Channel Colors.



Data and report setup

NOTE: For information on the Report Generation options, refer to “Report generation” later in this section.

1. To access the data and report setup:

• Select Setup from the Graph drop-down menu, and then select the Data and Report Options tab, or

• Right-click on the active graph, select Setup from the drop-down graph menu, and then select the Data and

Report Options tab, or

• Select Report Generation Setup from the Data & Reports drop-down menu.

2. Enter a title for the graph into the

Additional Information fields. This title

will appear at the top of the graph on each

printout.

3. Under Report Generation are options to

generate a report at the end of the test and

to save the report at each new level. You

can also choose to use the default report

template or choose a custom template, as

well as select to which folder to save

reports.

4. Select the desired response display from

the Display Band drop-down menu.

• To display frequencies outside of the

defined range of the test, select All

Energy.

• To filter out all noise and other energy

that does not apply to the test, select

Defined Energy.

5. To select the responses that you wish to

save each time the software stops, check

the Auto Save Data check box under Data

Files (.CSV).

• To send a copy of the data to the

printer each time the auto-save occurs,

check the Auto Hard Copy check box.

• To enable the Auto Save Data and

Auto Hard Copy at each level of the

test, check the Save at new level

check box.

The data is saved as a tab-delimited file under the test name, followed by a three-digit file extension that

increases each time you save the data. (for example, Sweep.000, Sweep.001, etc.). NOTE: In random mode

the response plots are saved. In sine mode the displayed graph data is saved.

• To save each pulse (in Shock mode only), check the Save each pulse check box and enter the maximum

number of pulses to save.

6. To accept your selections and exit, click OK.

7. To exit without saving any changes, click Cancel.



Saving and viewing historical test data

1. With a test loaded:

• Press Run on the control panel, or

• Select Run from the Command drop-down menu, or

• Press Ctrl+R.

2. To manually save all of the displayed graph data as a tab-delimited file, select Save Current Data from the Data

& Reports drop-down menu.

3. To display the saved data once a test is in stop mode:

a. Select View Saved Data from the Data & Reports drop-down menu.

b. Select the desired data file.

c. Repeat steps a and b for each file that you want to view.

4. To display the saved data as a spreadsheet, import the data file using a spreadsheet program. If the spreadsheet

format is not altered, the file can be re-imported into the WinVCS software as reference data.

Printing a graph

1. To print one or more graphs:

• Select Print from the File drop-down

menu, or

• Press the printer icon on the toolbar,

or

• Press Ctrl+P.

2. Select the desired Graph Layout.

3. Select the graphs to print.

4. To print your selections, click Print.

5. To exit without printing, click Cancel.

Report generation

WinVCS 2 Version 2.40 introduced a customizable report generation system. The setup dialog can be accessed by:

• Clicking Data & Reports on the menu bar and selecting Report Generation Setup, or

• Clicking Graph on the menu bar, selecting Setup, and then selecting the Data and Report Options tab, or

• Right-clicking a graph, selecting Setup from the drop-down menu, and selecting the Data and Report Options

tab.

The report generation settings are saved with each test profile, so each profile may have its own report format.

• Generate Report at End of Test: Check this to

automatically generate a report when a vibration

test completes. Reports also get generated if a test

aborts or is stopped manually.

• Save at each new level: If this is selected, reports

also get generated whenever a vibration test

transitions to a new level.

• Use Report Template: Select Default to use the

default supplied report template (each vibration

mode has its own default template). Select Custom

to specify a custom template that the user created.

Browse for a template by pressing the “…” button.

By default the templates are located in “C:\Program

Files\WinVCS 2\Report Templates” and can be used

as the basis for custom templates.

• Save Reports Here: Specifies the location where

reports are saved. If left blank, they are saved in the

WinVCS 2 installation folder, which by default is

C:\Program Files\WinVCS 2.

Report file names have the following format:

<name> Report-yyyy.mm.dd hh.mm.ss.rtf

For example, a test named NavMat would have a file name of:

NavMat Report-2009.01.29 09.31.14.rtf

To save a report at any time while a test is running, select Generate Report from the Data & Reports menu.

The reports may be viewed from any RTF viewer; however, WordPad, the viewer built into Windows, does not support

many of the features used by the default templates. We recommend using the free Microsoft Office Word Viewer,

available for download from Microsoft.

Customizing templates

Templates can be created by inserting special keywords into any text-based file format. The Rich Text Format (.rtf) is

used by default as it is easily readable by modern word processors such as Microsoft Word. Also supported are plain

text files (.txt) and comma-delimited files (.csv) for easy importing into spreadsheet programs. NOTE: Graphs may be

inserted only into Rich Text Format (.rtf) files.

Choose a custom template by selecting Custom under the Use Report Template selection on the Data and Report

Options page. Browse for a template by clicking the button marked “…” next to the template file name box.

The default templates are located (by default) in “C:\Program Files\WinVCS 2\Report Templates” and may be copied

and used as the basis for custom templates. All graphics and text not contained in “%” designations that are in the



default templates may be replaced without affecting the data that will be generated when that template is used to

generate a report. For example, the Thermotron logo may be replaced with the customer’s corporate logo.

The following list of keywords will insert text or graphics into a report reflecting current data at the time the report is

generated. The strings listed in the All vibration modes table will work regardless of the current WinVCS 2 vibration

mode. All other commands will work only if that vibration mode is currently active.

All vibration modes

%DATELONG% The current date in long form (for example, “Tuesday, August 24, 2016”)

%DATE% OR %DATEMDY% Short form date, American format (for example, “08/24/2016”)

%DATEDMY% Short form date, dd/mm/yyyy (for example, “24/08/2016”)

%TIME% Current time, hh:mm:ss

%FILENAME% File name of the currently running test

%INFO1% First line from the “Additional Information” fields of the report options

%INFO2% Second line from the “Additional Information” fields of the report options

%STARTTIME% The time the test started

%LEVEL% The current level of the test

%TOTALLEVELS% The total number of levels in the current test

%TOTALTIME% The total time of the current level of the test

%TESTLEVELPROGRESS% Shows the current progress through the current level

%REMAININGTIME% The time remaining in the current level

%CURRENTTESTDEFINITION% The entire definition of the currently loaded test

%TESTSTATUS% Returns “RUNNING” if a test is running or “HOLDING” if a test is currently in

hold mode. If stopped, it returns “STOPPED at hh:mm:ss on mm/dd/yyyy”.

%TESTDURATION% The amount of time the test ran (or has run, if it is still running). The format

is “a days, b hours, c minutes, d seconds”. Days are indicated only if the test

has run for more than 24 hours.

Random mode

%RANDOMCONTROLRMS% The current G RMS level of the control channel

%RANDOMCHANNELRMSn% The current G RMS level of the specified channel ‘n’

%RANDOMDRIVERMS% The voltage RMS level of the output signal

%RANDOMGRAPHREF% Reference graph for the current test

%RANDOMGRAPHCONTROL% Graph with the control accelerometers’ response PSD plotted

%RANDOMGRAPHMONITOR% Graph with the monitor accelerometers’ responses plotted

%RANDOMGRAPHDRIVE% Graph with the drive output plotted

%RANDOMGRAPHTRANS% Graph with transmissibility plotted



Sine mode

%SINETARGETG% The target G level (peak) at the current frequency in the current sine test

%SINECONTROLG% The response G level (peak) from the control accelerometer(s)

%SINECURRFREQ% The current frequency that the sine test is operating at

%SINEDRIVEOUT% The voltage output level (peak) at the current frequency

%SINEGRAPHREF% Reference graph for the current test

%SINEGRAPHCONTROLACCEL% Acceleration graph for the control channel(s)

%SINEGRAPHCONTROLVEL% Velocity graph for the control channel(s)

%SINEGRAPHCONTROLDISP% Displacement graph for the control channel(s)

%SINEGRAPHMONITORACCEL% Acceleration graph for the monitor channel(s)

%SINEGRAPHMONITORVEL% Velocity graph for the monitor channel(s)

%SINEGRAPHMONITORDISP% Displacement graph for the monitor channel(s)

%SINEGRAPHDRIVE% Graph with the output drive plotted

%SINEGRAPHTRANS% Sine mode transmissibility graph

Shock mode

%SHOCKTARGETG% Target peak G level for this shock test

%SHOCKCONTROLG% Peak G level of the response accelerometer

%SHOCKDRIVEOUT% Peak voltage level of the drive output

%SHOCKGRAPHREF% Reference graph for the current test

%SHOCKGRAPHACCEL% Acceleration response graph for all channels

%SHOCKGRAPHVEL% Velocity response graph for all channels

%SHOCKGRAPHDISP% Displacement response graph for all channels

%SHOCKGRAPHDRIVE% Graph with the output drive plotted



Accessing the test options

Each vibration mode has its own test options. For specific mode test options, refer to the “Random Mode,” “Sine

Mode,” “Shock Mode,” or “RealData Mode” section later in this manual.

NOTE: Any changes made to the test options will affect the loaded test as soon as the System Properties panel is

closed by clicking OK. When a parameter is changed, an asterisk appears next to the file name at the top of the main

window indicating that the file has unsaved changes.

1. Select Test Setup from the Options drop-down

menu, or press the Test Setup button on the

control panel. The System Properties panel for the

defined test is displayed. The image to the right

shows the Sine Control System Properties panel.

2. Select one of the tabs to display the desired test

definition panel. These panels provide access to all

of the parameters that define a test.

• To apply any changes to the test and exit the

System Properties panel, click OK.

• To close the panel without saving any changes,

click Cancel.



Safety parameters function

All shakers are limited by their force, velocity, displacement, and frequency specifications. These specifications impose

limits on the tests that you can run on the system. The WinVCS 2 safety parameters function calculates the peak force,

load, velocity, and displacement of a test to ensure the test is within the limits of the shaker. CAUTION: The safety

parameters function does not calculate force or velocity limits for shock mode tests, as these limits depend on

the test as well as the shaker. Call Thermotron Product Support for specific shock rating curves for your shaker

system.

Modifying the fixture and product weight settings

1. With the desired test loaded, press Config. The Shaker

Parameters dialog box will appear.

2. In the Fixture field, enter the mass of your fixture in pounds.

3. In the Product field, enter the mass of your product in pounds.

CAUTION: Be sure the information you enter is accurate.

Calculations based on inaccurate information can lead to

damage to the shaker, fixture, and product under test.

4. Indicate the current shaker orientation by clicking either Vertical

or Horizontal.

5. Select a method to generate displacement warnings in random

mode. For more details see “Shaker limits in random mode” in

Section 2 of this manual.

6. To accept the displayed values, press OK. Your settings will be

saved and the dialog box will close.

7. To close the dialog box without saving any changes, press Cancel.



Modifying the force and shaker ratings

CAUTION: Modifying the force, velocity, and displacement parameters affects safety checks. This procedure is

normally performed once for each shaker, and on new systems it is performed at the factory. The user should

not modify the factory settings.

1. Press the Config button. The Shaker

Parameters dialog box will appear.

2. Press the blank button in the lower left-

hand corner. A message will appear

warning you that modifying the shaker

parameters affects safety checks. To

proceed, press Yes.

3. You can now edit the following shaker parameters:

• Force Ratings: There are separate settings for sine and

random. For most shakers these will be the same value, but

some shakers can be tuned to favor either random or sine,

in which case these values will be different. Refer to the

specifications page in your Shaker Body Instruction Manual.

• Shaker Ratings: Velocity and displacement limits are

defined per shaker. Refer to the specifications page in your

Shaker Body Instruction Manual.

• Amplifier Settings: The WinVCS 2 software uses this value

to determine what level of field it should run when saving

power, and what to run when power saving is disabled.

NOTE: If the Maximum Field Adjust value is not set,

contact Thermotron Product Support.

CAUTION: Be sure the information you enter is accurate.

Calculations based on inaccurate information can lead to

damage to the shaker, fixture, and product under test.

4. To accept the displayed values, press OK. To close the dialog box without saving any changes, press Cancel.

Recalculated shaker parameters

CAUTION: If a test exceeds the shaker limits, WinVCS 2 will warn you before you run the test. If you choose to

run the test anyway, you risk damaging the shaker.

Based on the currently loaded test and the shaker parameters you entered, the WinVCS 2 software will recalculate the

Force, Load, Velocity, and Displacement fields located to the left of the Config button.

• If the proposed test is within the limits of the shaker, all relevant indicators will be green.

• If the test approaches the limits of the shaker, one or more indicators will be yellow.

• If the test exceeds the limits of the shaker, one or more indicators will be red.

If the test is not within the limits of the shaker, perform one of the following:

• Change the current test parameters, or

• Adjust the test payload and then re-enter the shaker parameters.



Power savings

When enabled, the power savings option will reduce the power that a test consumes by dynamically reducing the

amplifier field setting. The amount of power saved depends on what type of test is being run.

NOTE: By default power savings is disabled for Random and RealData (RDAP) modes. Starting in WinVCS 2.90 power

savings is not available in Shock and Sine modes. Enable Power Savings disables Use Preset Field.

Enabling power savings

On the Amp Control tab of the test options for all types

of test there is an Enable Power Savings option, shown

here in the random test options:

To enable this feature, the Maximum Field Adjust

setting must be set correctly in the shaker parameters

configuration screen. The WinVCS 2 software uses this

value to determine what level of field it should run when

saving power, and what to run when power saving is

disabled and no Preset Field is specified.

NOTE: If the Maximum Field Adjust value is not set,

contact Thermotron Product Support.



The current status of the power setting mode is displayed in an indicator above the individual input status fields along

the left side of the screen:

• If power saving is enabled for the current test, the indicator glows green:

• If power saving is disabled for the current test, the indicator is grayed out:

• If the Maximum Field Adjust setting has not yet been set and power

savings is unavailable, the message Max Field Not Set is displayed:

If the setting is not enabled for a particular test, that test will run at the Maximum Field Adjust setting by default.

NOTE: On most systems even full force tests may benefit from power savings mode. However, if you are having

trouble running a test, try disabling power savings to see if the system needs the extra power to run.

A custom field setting of your choosing may be used by enabling the Use Preset Gain option on the Amp Control

tab. This setting is disabled while power savings is enabled.



Running a test

For information on defining a new vibration test, refer to the “Random Mode,” “Sine Mode,” “Shock Mode,” or

“RealData Mode” section later in this manual. For information on loading a pre-existing test, refer to “Loading an

existing test” earlier in this manual.

1. To run a test, press Run on the control panel, select Run from the Command drop-down menu, or press Ctrl+R.

a. All tests begin at Level 1. The software checks the response of a low level signal. Once the response is

detected, the system starts up according to the start parameter on the level schedule.

NOTE: A model start or resume start can be defined for a random test. When a random test begins the

software looks for a stored drive. If a drive was saved the last time the test was run, the saved drive is used. If

there is not a saved drive, the drive is equalized to the Level 1 output. For the model start and resume start

procedures, see “Using a model or resume drive” in the “Random Mode” section later in this manual.

b. Once the signal equalizes within the tolerance limits, the clock starts counting for the current level.

c. Once the clock times out, the test moves to the next level:

• If the next level has a saved drive, that drive is used.

• If the next level does not have a saved drive, the drive is equalized to the level’s defined output.

d. Steps b and c are repeated until all levels are executed.

2. To move up or down the level schedule, select Next Level or Previous Level from the

Command drop-down menu or toolbar during a test:

• If the selected level has a saved drive, that drive is used.

• If the selected level does not have a saved drive, the drive is equalized to the level’s defined output.

3. To operate a test in the hold state:

a. Select Hold from the control panel or the Command drop-down menu. The Run lamp flashes yellow.

b. A fixed drive at the current level is output, the clock is stopped, and limit checking is suspended.

c. To continue the test from hold, select Run or Resume. Either command continues the test from the current

drive and clock setting, and re-enables limit checking.

4. To stop a test, select Stop from the control panel or the Command drop-down menu.

NOTE: Pressing Resume while a test is stopped will start the test with the previous time left.

5. To send a copy of selected test data to a printer or a file:

• To print the defined test options, select Print Test Definition from the File drop-down menu.

• To print the active graph, select Print from the File drop-down menu or toolbar.

• To send a copy of the active graph to the Windows clipboard, select Copy from the Edit menu or toolbar.

• To store test data, see “Saving and viewing historical test data” earlier in this section.



Assigning and running a test schedule

The Test Schedule function allows several tests to be run consecutively. A test schedule can be a mix of all modes.

Additionally, up to seven test schedules can be run via digital I/O.

1. Select Schedule Tests from the Options drop-down

menu.

2. To open a blank table, click the New Schedule button.

3. To open an existing test schedule, click the Open

button:

a. The Open dialog box displays the available test

schedules.

b. Select the desired test schedule from the default

folder or browse to another location. NOTE: All test

schedules have the *.sch file extension.

c. To load the selected test schedule, click the Open

button.

d. To close the dialog box without loading a test

schedule, click the Cancel button.

4. To add a test to the test schedule:

a. Select the desired line.

b. Click the Browse button.

c. The Open dialog box displays all the test files (*.vcs) in the default folder.

d. Select the desired test.

e. To load the selected test, click the Open button.

f. To close the dialog box without loading a test, click the Cancel button.

5. To remove a line, select the desired test and press the Delete key.

6. To edit a line, select the desired row, highlight any existing text, and type the new file path and name.

7. To save the test schedule, click the Save As button. Save the test schedule using the *.sch file extension.

8. To run the displayed test schedule, click the Run Schedule button. The tests are run in the order listed on the

schedule.

9. To assign different test schedules for remote operation:

a. Click the Schedule Index button to open the

Remote Schedule Index panel.

b. Click the Browse button by the index line you want

to edit.

c. The Open dialog box displays all the test schedules

(*.sch) in the default folder.

d. Select the desired test schedule.

e. To apply any changes and exit the panel, click OK.

f. To close the panel without saving any changes, click

Cancel.

NOTE: Each schedule assigned to an index can be run

from a remote Thermotron programmer/controller.



Disable blower function

WinVCS 2 Version 2.34 introduced a feature that enables the user to disable the blower for up to 15 minutes at a

time. This enables the user to take sound measurements for “squeak and rattle” tests where ambient noise needs to

be reduced or eliminated.

Disabling the blower

When the system is properly configured and a test is running, the icon shown to the right will be enabled in

the toolbar. To disable the blower, press this button. The following conditions must be met:

• The Field Adjust parameter for the amplifier must be set to 40 or less.

• The Armature Current cannot exceed 100A.

• The currently calculated Force must not exceed 1,000 lbf.

If the above three conditions are satisfied, the blower will shut off immediately; otherwise a message will be displayed

explaining which condition is not met. Once the blower is disabled, it will remain off until one of the following

conditions is met:

1. The user clicks the icon again.

2. Fifteen minutes elapse.

3. The test is stopped (which will usually trigger the blower to go into its cool-down period if it needs to).

4. The Field Adjust setting is manually set above 40.

5. The test goes to a level that causes the Force to exceed 1,000 lbf.



Abort messages

The messages below have the format “Abort: message [status info]” and are colored red in the WinVCS event log. The

information inside the brackets contains test-specific information, such as test level and the control response level at

the time of the abort.

Several of the Cause/Solution sections direct you to your local Field Service office or to Thermotron Technical

Support. Contact Thermotron Technical Support at (616) 392-6550 or via e-mail at [email protected].

Test limit messages

Control

Sine and random mode only. In sine mode it simply means the control response has gone outside of the defined

abort limit while the test had already been running. In random mode it means the number of points defined in

the random test definition’s “Control Abort Lines” have gone outside of the defined abort limits (again, while the

test had already been running).

Cause/Solution: Check the accelerometer placement to ensure it is secure on the established position on the

armature or slip plate. Unexpected changes to the load — for example if something broke or came loose on the

UUT — may also cause this error. The accelerometer positions must be established for each test based on the

test profile, product load, and product fixtures. For more information, see the Product Test Application Manual.

Control Accel Error

RDAP mode only. An unexpected spike happened on the input accelerometer during RDAP test startup.

Cause/Solution: While calculating the characteristics of the system, an invalid response was detected on the

control channel. This usually indicates a problem with the accelerometer or accelerometer cable.

1. Check the coaxial cable connections from the VIO module to the accelerometer.

2. Check the accelerometer connections, and make sure that the accelerometer is mounted securely.

3. Finally, check the accelerometer.

Raw Control RMS

Random mode only. The unaveraged RMS level measured in the time domain of the control channel (as opposed

to individual frequency lines) has spiked too high or dipped too low. The threshold is defined in the test’s abort

parameters.

Cause/Solution: This usually means something physically went wrong on the test product, fixture, accelerometer,

or accelerometer cable, causing a sudden spike or dip in the RMS level. Check that the WinVCS software is not

seeing significant response outside the defined bandwidth of the test. For more information, see the Product Test

Application Manual.

Control RMS too high

RDAP mode only. The RMS level of the control channel spiked too high. The threshold is defined in the test’s

abort parameters.


or accelerometer cable, causing a spike in the RMS level. For more information, see the Product Test Application

Manual.

Control RMS too low

RDAP mode only. The RMS level of the control channel dipped too low. The threshold is defined in the test’s

abort parameters.


or accelerometer cable, causing a dip in the RMS level. For more information, see the Product Test Application

Manual.

Internal Error 1

Sine mode only. An unexpected error occurred.

Cause/Solution: The test definition may be corrupt. Contact Thermotron for assistance.

Limit Reached

Shock mode only. The control channel has gone outside of the defined abort limits (represented by the red lines

on the screen).

Cause/Solution: This usually happens if something physically went wrong during the test, or it is possible the

test was running very close to the abort limits to begin with. Check the test profile and the actual load mass on

the armature. Make sure that your test calculations are correct. If possible, use Adaptive Shock or switch to a “low

g” reference. For more information on setting up the test, see the Product Test Application Manual.

Max Peak Output

Sine mode only. The voltage output (peak, not RMS) has exceeded the defined maximum.

Cause/Solution: You may raise the start voltage output up to a limit of 10V. If the problem persists, there is a

problem with the system or the test cannot be run. Check the test profile and the actual load mass on the

armature. Make sure that your test calculations are correct. For more information on setting up the test, see the

Product Test Application Manual.

Max Run Output

Shock mode only. The output voltage while the test was running exceeded the limit defined in the test’s abort

parameters.

Cause/Solution: You may raise the voltage output up to a limit of 10V. If the problem persists, there is a problem

with the system or the test cannot be run. Check the test profile and the actual load mass on the armature. Make

sure that your test calculations are correct. For more information on setting up the test, see the Product Test

Application Manual.

Max Start Output

Shock mode only. The output voltage during test startup exceeded the limit defined in the test’s abort

parameters.

Cause/Solution: You may raise the start voltage output up to a limit of 10V. If the problem persists, there is a

problem with the system or the test cannot be run. Check the test profile and the actual load mass on the

armature. Make sure that your test calculations are correct. For more information on setting up the test, see the

Product Test Application Manual.

Monitor, channel n: <value>

Sine and random mode only. Similar to “Abort: Control” except the limit violation occurred on one of the defined

monitor channels; n is the number of the channel that had the fault and <value> is the response of that channel

in the appropriate units.

Cause/Solution: Check the location of the accelerometer that caused the fault for damage or loosening of the

UUT. If you do not want the test to abort when a monitor channel is outside of the limits, select the “Disable

Monitor Limits” option on the test’s Monitor Limits page.

No Peak Found

Sine mode only. The control accelerometer’s response is not a valid sine wave.

Cause/Solution: This is probably caused by a short on the control input or a DAQ card fault that developed

while the test was running.

1. Check the coaxial cable connections from the VIO module to the control accelerometer.



No Segment Data

Sine mode only. The test definition is incomplete.

Cause/Solution: Check the “Segments” tab in the test options.

Open Loop

During test startup, the output level has increased without a proportionate increase on the input. This means the

test cannot be run within the defined voltage limits, and has been aborted before the output level got too high.

Cause/Solution: Either there is an open connection somewhere (for example, the output from the VIO is

unplugged), or the defined voltage limits are set too low to run the test.

1. Check that the Max Start V RMS and Max Run V RMS (Random, Abort Parameters tab), the Start Peak

Output and Peak Output (Sine, Test Profile tab) or the Start Limit and Run Limit (Shock, Test Limits tab)

are set to appropriately high values. Check that Use Preset Gain (all modes, Amp Control tab) is checked

and not set to zero.

2. Check the output connections at the VIO module and its cable connection at the machine controller.

3. Check the coaxial cable connections from the VIO module to the control accelerometer.



Running V RMS

Random and RDAP modes only. While running the test, the V RMS limit was exceeded.

Cause/Solution: You may raise the defined V RMS limit, up to a practical limit of 3.3V. If the error persists, there

is either a problem with the test setup or the test cannot be run. Check the test profile and the actual load mass

on the armature. Make sure that your test calculations are correct. For more information on setting up the test,

see the Product Test Application Manual.

Start V RMS

Random and RDAP modes only. During test startup, the voltage output exceeded the defined “Start V RMS” limit.

Cause/Solution: You may raise the defined Start V RMS limit, up to a practical limit of 3.3V. If the error persists,

there is either a problem with the test setup or the test cannot be run. Check the test profile and the actual load

mass on the armature. Make sure that your test calculations are correct. For more information on setting up the

test, see the Product Test Application Manual.

Amplifier/machine controller-related messages

Amp Comm Loss

Displayed if the controller PC suddenly loses communication with the amplifier and the controller is configured to

stop on loss of communication (default setting).

Cause/Solution: The most likely cause of this message is a loose cable at one of four locations:

• The COM port on the PC

• The 9-pin serial port input on the VIO module

• The Amp TBus port on the VIO (J11)

• The Amp TBus port on the machine controller

Check all connections and make sure they are secure.



Amplifier Fault n: fault

The machine controller has reported an error to the WinVCS controller. There are 24 possible machine controller

faults, listed below:

1: HI ARM I

The amplifier has exceeded its defined maximum allowed current and has shut down to protect itself from

damage.

Cause/Solution: The test being run may exceed the capabilities of the system. Make sure the force rating of

the shaker is not being exceeded given the current G level and payload. Check the test profile and the actual

load mass on the armature. Make sure that your test calculations are correct. For more information on

setting up the test, see the Product Test Application Manual.

If the problem persists, check the system connections. For detailed troubleshooting information, see the

“Shaker Body Sensor Fault Codes” section of the Shaker Body Instruction Manual.

2: HI FIELD I

The field current has exceeded its maximum allowed amperage.

Cause/Solution: This may indicate that the machine controller safety limits are set incorrectly (preset at the

factory; do not modify), or a more serious problem has occurred with the amplifier or shaker itself. Contact

Thermotron Technical Support.

3: LO FIELD I

The field current has failed to reach the level desired by the controller.

Cause/Solution: This may indicate that the machine controller safety limits are set incorrectly (preset at the

factory; do not modify), or a more serious problem has occurred with the field power supply, interconnect, or

shaker itself. Contact Thermotron Technical Support.

4: HI DGS I

Degauss coil current has exceeded its maximum allowed amperage.

Cause/Solution: Only applicable to DS1000 or DS1200 shakers. Contact Thermotron Technical Support.

5: AHVPS VOLT

The amplifier’s inverter power supply is reading incorrectly.

Cause/Solution: The power transformer is tapped incorrectly or the incoming line voltage is too high.

Contact Thermotron Technical Support.

6: AHVPS TEMP

The amplifier’s inverter power supply temperature limit has been exceeded.

Cause/Solution: Check that the amplifier console has all fans operating, all intake and exhaust vents are

clear and unobstructed, and the console door is closed.

7: FHVPS TEMP

The field power supply temperature limit has been exceeded.

Cause/Solution: Check that the amplifier console has all fans operating, all intake and exhaust vents are

clear and unobstructed, and the console door is closed.

8: INVERTER

One or more of the inverter modules has reported a serious fault.

Cause/Solution: This may indicate damage to one or more of the inverters, or possibly an error in the wiring

of the system. Check the status LED’s on the front of the inverters.



9: SHAKER TEMP

The shaker temperature limit has been exceeded.

Cause/Solution: Check that the blower is configured correctly and operational. For detailed troubleshooting

information, see the “Shaker Body Sensor Fault Codes” section of the Shaker Body Instruction Manual.

10: SHAKER VAC

The blower system feedback is indicating a failure.

Cause/Solution: Check that the blower has power and is turning on correctly. For detailed troubleshooting

information, see the “Shaker Body Sensor Fault Codes” section of the Shaker Body Instruction Manual.

11: S-P OIL

For horizontal systems, the slip plate’s oil flow switch is not sensing an adequate flow (in oil film slip tables)

or the oil pressure is too high or low (in bearing line tables).

Cause/Solution: There is likely a problem with the oil system on the slip plate. Operation could result in

serious damage to the slip plate. To check, see the EDV Slip Table Instruction Manual.

12: OVERTRAVEL

The DCS sensor has indicated the shaker armature has either traveled too high or too low and has shut down

to prevent physical damage.

Cause/Solution: Ensure the defined test is within the shaker’s travel limits. If you believe this message to be

an error, it may indicate that the flag affixed to the armature that is used to indicate its position is out of

alignment. See “Checking the DCS Sensors” in Section C of the Shaker Body Instruction Manual. If the DCS

sensors are out of adjustment, contact Thermotron Technical Support.

13: DCS OPN LP

The dynamic centering system is not able to raise or lower the shaker by filling and draining the airbags.

Cause/Solution: Check the system for air leaks and sufficient air pressure. See “Verifying Shaker Operation”

in Section D of the Shaker Body Instruction Manual.

14: DGS OPN LP

The degauss coil current is not controllable.

Cause/Solution: Only applicable to DS1000 or DS1200 shakers. Contact Thermotron Technical Support.

15: CP AUX IN

An input on the control panel has indicated an invalid state.

Cause/Solution: This is typically only seen on systems that have been updated to have both a physical

control panel as well as communication via TBus from the WinVCS controller. This message may appear if the

WinVCS software is started or shut down while the amplifier is in the run state. It can be safely cleared and

ignored.

16: EEROM FAIL

An internal check of the machine controller has revealed an unrecoverable error.

Cause/Solution: The machine controller must be serviced or replaced by an authorized Thermotron

technician.

17: MC AUX IN

An input on the machine controller has indicated an invalid state.

Cause/Solution: This input is not usually used, and may indicate a jumper is missing on the machine

controller. Contact Thermotron Technical Support.



18: STEMP SENS

The shaker’s temperature sensor is indicating an invalid state.

Cause/Solution: A sensor is faulty. The system needs to be serviced by an authorized Thermotron

technician.

19: FTEMP SENS

The field current power supply’s temperature sensor is indicating an invalid state.


technician.

20: ATEMP SENS

The amplifier power supply’s temperature sensor is indicating an invalid state.


technician.

21: ARM I SENS

The armature’s current sensor is indicating an invalid state.


technician.

22: VACUM SENS

The blower’s pressure sensor is indicating an invalid state.


technician.

23: FLD I SENS

The field current’s sensor is indicating an invalid state.


technician.

24: LOST COMM

The machine controller aborted because it lost communication with WinVCS (or the control panel) while it

was running.

Cause/Solution: The software or workstation may have halted or reset in the middle of a test, or a cable has

come loose (check “Amp Comm Loss” above). If this message is displayed, however, it means communication

has been reestablished. Check the last action taken before the fault occurred.

Amplifier Fault ERROR

An unknown amplifier fault has occurred.

Cause/Solution: Record the error number (reported in the amplifier toolbar), report it to Thermotron Technical

Support, and check for WinVCS software updates.



Other messages

Accel Input n Fault (OPEN or SHORT)

The indicated accelerometer input has reported a problem.

Cause/Solution: An accelerometer cable came loose or was shorted while a test was running. Check all

accelerometer connections; the accelerometer cable may need to be replaced.

1. Check the coaxial cable connections from the VIO module to the accelerometer.


3. Finally, check the accelerometer and cables.

DAQ Error, code: n

The National Instruments DAQ card reported an error.

Cause/Solution: The codes vary depending on the National Instruments driver version, and there are too many

to list here. However, the timing of the error can tell us about the nature of the problem.

If the test aborts immediately with a DAQ error, before even attempting any vibration, it means one of the

following:

1. The card is installed but the address is wrong. Run NI’s Measurement & Automation Explorer and check the

NI-DAQmx devices; the card should be listed as “Dev1.” On older systems it may simply be a “1” as the

device ID.

2. The card’s drivers are corrupt. Find the National Instruments Software in the Windows “Add/Remove

Software” list, select “Add/Remove,” and select the “repair” option.

3. The “use 100k” setting is enabled on a card that does not support it. Clear this setting in the system options

and attempt the test again.

4. If these don’t work, the card may have a hardware failure. In Measurement & Automation Explorer, right click

on the card and select “Self Test.” If the card returns an error, contact Thermotron for instructions for

replacing the DAQ card.

If the test aborted somewhere in the middle of a test, retry and see if the same error code occurs again. If the test

now aborts immediately, follow the above steps to troubleshoot the card. If the test runs, it may abort again at

random points during a test. This could indicate an intermittent hardware problem in the DAQ card itself or

interference from another application or hardware installed on the controller workstation. To rule out the latter

case, ensure that no nonessential processes, such as virus scanners, indexing services, and web browsers, are

running on the workstation during a vibration test.

E-STOP PRESSED

Displayed when the emergency stop button is pressed. This message appears only if an E-Stop is configured and

wired into the VIO box.

Cause/Solution: This message should be displayed only if an operator presses the E-Stop button. If the E-Stop

was not pressed, it could mean the wiring of the E-Stop button came loose or shorted. Check and repair the E-

Stop wiring. If the problem persists, call Thermotron Technical Support.

WinVCS 2 Instruction Manual Random Mode


Section 2: Random Mode Random mode allows you to define, edit, run, and view random vibration tests. This section describes the random

mode graphs and provides procedures for defining and editing random mode tests. Special programming and

operating techniques are also described.

Random mode uses a concept called convolution. Convolution is a method of control used to produce the most

accurate signal possible on the shaker. Convolution allows tests to ramp up faster than previously possible.

Random mode graphs

The random mode graphs display the defined test as well as the real-time closed loop data during a test. The defined

test plots the desired response from the shaker. The real-time closed loop graphs display how the system is operating

to achieve the desired response.

Response

The Control Response and Monitor Response

graphs display the actual response from the control

and monitor accelerometers mounted on the

shaker or slip table.

Both control and monitor graphs can display

multiple channels. When multiple channels are

displayed along the bottom of a graph, press a

channel’s button to remove it from the display.

Press the button a second time to re-display the

channel.

• The Control Response graph displays the

response used to adjust the demand output to

the shaker. The control response is a part of

the closed-loop control system.

• The Monitor Response graph displays the

response of other areas around the product or

shaker. This response is calculated separately

and is not a part of the closed-loop system.

Each response graph can display the tolerance

and/or abort limits:

• The tolerance limits are the two lines closest to

the response line. They display the acceptable

amplitude limits for the test.

• The abort limits are the two outer lines. They

display the absolute amplitude limits of the

test. The test stops if the response exceeds

these limits.

Random Mode WinVCS 2 Instruction Manual


Output Drive

The Output Drive graph displays the actual

frequency-domain drive signal output to the shaker.

The graph shows the amplitude of the drive signal’s

voltage over the defined frequency range. The

software converts this signal to a time-domain drive

signal that is applied to the shaker amplifier

through the VCS I/O module.

Transmissibility

The Transmissibility graph displays the response

ratio between the monitor and control

accelerometers. The software plots the monitor

response divided by the control response (in g’s)

across the defined frequency band.

This graph can be used to find the resonant

frequencies of a product. To find resonances on a

product, place the monitor accelerometer on the

product and the control accelerometer on the

product fixture. As a test is run, observe the ratio

between the product and the fixture. The resonance

frequencies are the highest transmissibility peaks

between two channels.



Reference

The Reference graph displays the amplitude over a

defined frequency band. The demand plot is in the

center plot of the graph. You define or edit the

demand plot from the Reference panel described

later in this section. The demand plot defines the

response the closed-loop system is working to

achieve during the test. The demand plot can also

display the tolerance and abort limits:

• The tolerance band is displayed as the two

lines closest to the demand plot. They display

the acceptable amplitude limits for the test.

• The abort band is displayed as the two outer

lines. They display the absolute amplitude

limits of the test. The test stops if the response

exceeds these limits.

Real Time Input and Output

The Real Time Input and Real Time Output graphs displays the real time data for the current mode.

• The Real Time Input graph displays the time

domain G level for each enabled input

channel’s accelerometer.

• The Real Time Output graph displays the time

domain voltage level of the output signal.



Defining a new random test

The WinVCS 2 software provides a test definition wizard for each vibration mode. The random mode wizard takes you

sequentially through the random mode panels, allowing you to define a complete test. Once a test is defined, it is

loaded into the main window. You can also select Test Setup from the Options drop-down menu to define a new

random text.

1. Select the Random Mode button on the toolbar.

2. Select the New Test button on the toolbar.

3. The wizard loads and takes you through all the profile definition displays.

NOTE: To save a defined test, select Save Test or Save As from the File drop-down menu, the Save icon on the

toolbar, or press Ctrl+S.

Test Profile panel

The Test Profile panel allows you to set up the

overall characteristics of the test.

1. Select the maximum frequency limits of

your product or shaker from the Max

Frequency drop-down menu.

The Max Frequency field sets up the

bandwidth of the test. The demand plot will

run from 0 Hz to the defined frequency.

2. Select the number of lines for filter

resolution from the Lines of Resolution

drop-down menu. Increasing this value

gives more accurate results, but slower

loop times.

NOTE: The filter bandwidth is equal to the

Max Frequency setting divided by the

Lines of Resolution setting. Increasing the

filter bandwidth beyond 3.2 Hz does not

further decrease loop times.

3. In the Average Factor field enter the

number of frames of data to average

together before converting the data into a

response plot.

• A larger number provides a slower and

smoother response.

• A smaller number provides coarser control but a quicker response.

4. To enable sigma clipping, check the check box and enter the amount of sigma clipping in the Sigma Clipping

field. Sigma clipping removes very large spikes from the drive plot. The software multiplies the overall signal

VRMS level by the amount of sigma clipping to determine where it will clip the signal.

For example, a sigma clipping value of 3 will clip a 0.8 VRMS drive signal whose spikes exceed 2.4 VPK. The

shaker amplifier will not see any portion of this drive signal that exceeds 2.4 VPK. NOTE: To limit distortion, sigma

clipping should generally not be set below 3. The WinVCS software will clip drive voltages beyond ±9.95 V

regardless of sigma clipping.



5. Select the Control Channels and Monitor Channels to use by checking the appropriate check boxes.

6. If more than one control channel is selected, select the type of multi-channel control to use from the Multi-

Channel Control drop-down menu.

NOTE: Selecting multiple control channels prevents the software from using convolution during a test, and ramp-

up time will be increased.

7. Press the Advanced button to the access the advanced test options:

a. The Loop Adjust field defines the minimum number of loops that will get

done before adjusting. Leave this value at zero to use the default of 5 loops.

b. In the Control Gain field enter the desired control gain. The higher the

number, the faster the ramp-up. NOTE: DO NOT set the Control Gain

higher than 50, as this will create control instability. Control Gain has no

effect unless convolution is disabled.

c. In the Start Average field enter the desired start average. This is the

average factor used to bring a test to level.

d. In the Control Average field enter the desired control average. This value is

the number of averages used for control in WinVCS version 2.90 and earlier.

(It is not used in later versions.)

e. If kurtosis is required, check the check box and enter the value in the Kurtosis field. Activating Kurtosis

automatically deactivates Sigma Clipping.

NOTE: The Kurtosis feature is for meeting specifications only; it is not necessarily damage-equivalent to any

other kurtosis method. The kurtosis frequency is automatically set to the filter bandwidth of the test.

f. To stop the software from using convolution, check the Do not use convolution for control check box.

NOTE: Disabling convolution will increase ramp-up time.

g. To accept the displayed values, press OK.

h. To close the panel without saving any changes, press Cancel.



Amplifier Control panel (optional)

The Amp Control panel allows you to set up the amplifier control characteristics of the test. NOTE: The Amp Control

panel is available only when a Thermotron machine controller interface cable is used.

1. Enter the amplifier settings:

a. If gain recall is not enabled, check the

Use Preset Gain check box and enter

the preset gain value.

b. To use a preset field, check the Use

Preset Field check box and enter the

preset field. NOTE: This allows gain

and field settings to be saved per test.

2. To accept the displayed values, press OK.

3. To close the panel without saving any

changes, press Cancel.

For information on enabling power savings,

refer to “Power savings” in Section 1 of this

manual.



Abort Parameters panel

The Abort Parameters panel allows you to set up the abort limits of the test.

1. For active Control and Monitor channels:

a. Define how many lines of the

frequency resolution of the response

signal are allowed to cross the abort

limits before an abort occurs. The lines,

as defined in the Test Profile panel,

are vertical lines that are evenly spaced

across the frequency bandwidth.

Normally you would not want a stray

signal spike to cause an abort. This

parameter defines the allowable width

of the stray signal or cumulative width

of separate stray signals.

NOTE: The Control or Monitor field

affects its respective response profile

only.

Normally, the abort lines are set to five

percent of the total lines. For example,

in a test with 400 lines, there should be

20 abort control lines. If the control-

input channels indicate PSD levels

outside the defined Abort ±dB limits at

more than 20 lines, the test will stop. If

the PSD levels are outside the Abort

±dB limits at 19 lines, the test will not

stop.

The Max Control RMS and Min Control RMS values set how many dBs the un-averaged RMS can be off

before a test aborts.

b. To disable the abort lines, set the parameter to a value greater than or equal to the Lines of Resolution field

in the Test Profile panel, then set the corresponding RMS fields to 0.00.

2. In the Max Start V RMS field, define the maximum drive output (VRMS) allowed while the test is ramping up to

the first level. NOTE: The NI-DAQ card cannot output drive signals above 3.33 VRMS without significant

distortion.

3. In the Max Run V RMS field, define the maximum drive output (VRMS) allowed during the test. NOTE: The NI-

DAQ card cannot output drive signals above 3.33 VRMS without significant distortion.

4. Select the condition to begin counting test time. You can select one of the following:

• The response spectrum is within the defined tolerance band.

• The control RMS response has met or exceeded the reference RMS.


6. To close the panel without saving any changes, press Cancel.



Reference panel

The Reference panel defines the demand plot for the test. The demand plot sets the parameters for the desired

response from the shaker. The software develops the drive output to the shaker amplifier based on this plot, and

modifies the drive to maintain a control response that is within the tolerance limits of the test.

1. In the Frequency (Hz) field, enter a

frequency breakpoint within the defined

bandwidth. NOTE: The first and last

breakpoints determine the bandwidth of

the test. Make sure the bandwidth is within

the performance specifications of your

shaker.

2. In the PSD (G2/Hz) field, enter the defined

PSD level between two breakpoints.

3. In the Slope (dB/Oct) field, enter the

defined slope between two frequencies.

NOTE: To use this value, set the PSD field

to zero on the same or next line. Once you

define the test or finish editing the test

options, the software calculates the PSD for

the zero field based on the slope.

4. To import data directly from a saved data

file, press the Import button. NOTE: If the

stored data file was created with

Thermotron Vibration Control Software

version 1.1 or earlier, you must first select

View Saved Data from the Data &

Reports drop-down menu, and then re-

save the file. The file will be reformatted

and renamed. The older version can then

be deleted.

5. To add a line to the table, press the New Row button.

6. To clear all the data from the table, press the Clear Data button.

7. The Reference Preview displays a small graph of the values selected in the Reference panel.





Control Limits panel

The Control Limits panel defines how far the control input channels’ response profiles can deviate from the demand

profile. NOTE: The table automatically re-sorts by frequency. Enter all values in positive dB units.

1. In the Frequency field, enter a frequency

breakpoint within the defined bandwidth.

NOTE: There is no need to specify upper

limits. Each segment extends upward from

the entered Frequency.

2. In the Tol +dB field, enter the tolerance

limit above the demand plot.

NOTE: The control response must stabilize

below this limit before the test clock starts.

Once the clock starts the software issues a

warning any time the control response

exceeds the limit, and the drive is adjusted

to stay below the limit.

3. In the Tol -dB field, enter the tolerance

limit below the demand plot.


above this limit before the test clock starts.

Once the clock starts, the software issues a

warning any time the control response

exceeds the limit, and it adjusts the drive to

stay above the limit.

4. In the Abort +dB field, enter the abort limit

above the demand plot. Once the clock

starts, the software stops the test any time

the control response crosses the limit as defined in the Abort Parameters panel.

5. In the Abort -dB field, enter the abort limit below the demand plot. Once the clock starts, the software stops the

test any time the control response crosses the limit as defined in the Abort Parameters panel.





Monitor Limits panel

The Monitor Limits panel defines how far the monitor-input channels’ response can deviate from the demand plot.

NOTE: The table automatically re-sorts by frequency. Enter all values in positive dB units.

1. To disable the monitor limits, check the

Disable Monitor Limits check box at the

bottom of the Monitor Limits panel.

Uncheck this check box to enable the

monitor limits.

NOTE: If you disable the monitor limits, the

software issues warnings or stops the test

based on the control limits alone.







limit above the demand plot. Once the

clock starts, the software issues a warning

any time the monitor response exceeds the

limit, and adjusts the drive to stay below

the limit.


limit below the demand plot. Once the



limit, and adjusts the drive to stay above

the limit.

5. In the Abort +dB field, enter the abort limit above the demand plot. Once the clock starts, the software stops the

test any time the monitor response crosses the limit as defined in the Abort Parameters panel.


test any time the monitor response crosses the limit as defined in the Abort Parameters panel.

NOTE: Program the monitor limits to allow greater deviations from the demand plot than the control limits,

because the software will not adjust its output to compensate if the monitor channel response deviates outside

the monitor limits. If tighter limits on the monitor channels are programmed, the software could stop the test

before the control response indicates an out-of-tolerance condition.





Level Schedule panel

The Level Schedule panel allows you to operate the test at different levels in relation to the reference profile. Each

level runs for a defined time before moving to the next level.

1. In the Test Time field, enter the duration of

the level. Once the control response is

within the tolerance limits of the test, the

software starts the test clock and begins

counting up to this value.

2. The fields in the next three columns adjust

the level of the demand profile’s output

without changing the shape of the test.

NOTE: Only one of these fields can be

programmed per level. If more than one is

programmed per level, the software selects

the leftmost non-zero field as the output

value.

• In the dB Level field, enter the number

of dB’s below the full test level that the

software will run the test. NOTE:

Typical dB Level values are negative to

run the test below full level. Entering a

positive dB Level will cause the test to

run above the defined level.

• In the G rms Level field, enter the

actual G rms level of the test.

• In the % Level field, enter the percent

of the demand profile that the

software will output. This is a percentage of the reference PSD, not the reference Grms. For example, the 50%

level of a 10 Grms test will run at 7.07 Grms, not 5.0 Grms.

3. Select the desired start parameter from the Start drop-down menu:

• Normal starts the scheduled test once the full equalization process is completed. The drive is equalized at

several points until it reaches full equalization.

• Model allows you to save the drive output for the scheduled test. When you run a test, the software looks

for a saved drive. If a saved drive is not available, a normal start is performed. Once a successful run at a

specific level is complete, press Ctrl+D to save the drive. Once a model drive is saved, the software equalizes

from the drive each time it moves to that level. For more information, see “Using a model or resume drive”

later in this section.

• Resume performs the same function as the model drive automatically. The drive is saved at the end of each

successful run.





Using a model or resume drive

CAUTION: Applying a saved drive to a test with modified load or output requirements could damage the

shaker! To prevent damage to the system, clear the drives from the modified test before running the test. You

can then redefine the model drives for the test according to its new drive or load requirements.

Some random tests can require a few minutes to

equalize the drive output at the desired level.

Model drives eliminate the equalization time by

immediately applying a known drive output to

the shaker. You can define the Level Schedule

panel’s Start mode parameters for a Model or

Resume start:

• Model allows you to save manually each

drive once it equalizes to the different levels

of the test. The first time you run the defined

test, WinVCS equalizes to each level. Once

the output equalizes and the test starts, you

can save the drive for that level.

• Resume automatically saves the WinVCS

program drive the first time you run the test.

The drive is saved at the end of each

successful level that has been run.

Either mode stores a drive that is used on any

tests that follow using the same test file. When

WinVCS runs a test with saved drives, it moves

quickly between levels by immediately going to

the saved drive output. Model requires manual

involvement to save each drive at each level,

Resume is automatic and the drive is only saved

after a successfully completed run. To use either

Resume or Model drives, the Start selection must be in the same condition, Resume to use resume drives, and

Model to use model drives.

NOTE: Saved drives are not directly used and have no effect on equalization time when convolution is enabled. To

bring a test to level safely in a short time, use convolution.

Storing or erasing model drives for a test

1. Open or create a test.

2. To erase the stored drives for the defined test, select the Clear Stored Drives command from the Data &

Reports menu.

a. WinVCS erases all the stored drives for the defined test.

b. The test will now equalize at each level.

3. Select the RUN button to start the test.

4. Watch the Control Response graph (random mode) or the Acceleration graph (shock mode) as the system

equalizes between the tolerance limits.

5. Wait until the response or acceleration plot is fully contained inside the tolerance limits.

a. The Warning lamp remains dark once the full signal is within the tolerance limits.

b. Once WinVCS determines that the output is equalized, it starts the clock for the current level.



6. To save the drive, press Ctrl+D or select Save Drive from the Data & Reports menu.

7. Perform one of these steps:

• Wait until the test moves to the next level in the level schedule.

• Select the Next Level command or toolbar button to move the test to the next level.

8. Repeat steps 5 through 7 for each test level where you wish to save a drive. Remember, the test level must be

defined for a Model Start mode.

9. To erase the stored drives for the defined test, select Clear Stored Drives from the Data & Reports menu. The

test now equalizes at each level.

Editing an existing test

Once a test is defined it can be modified to meet changing test needs. A new test can also be created from a pre-

existing test. A test can be edited in any operating state (run, stop, or hold), but any changes to control parameters

will cause the test counter to reset and may abort the test.

1. Load the desired test.

2. Press Test Setup on the control panel, or

select Test Setup from the Options drop-

down menu.

3. Select the desired tab to bring the panel to

the front.

4. Edit the parameters as described in

“Defining a new random test” earlier in this

section.

5. Repeat steps 3 and 4 to edit another panel.




8. To save the test under its original name,

press the Save button. To save the test

under a new name, select Save As from the

File drop-down menu.



Sine on random mode (optional)

The sine on random feature of the WinVCS 2 software is an option that can be purchased in addition to the standard

software. The sine on random application works in conjunction with random mode. Sine on random (SOR) allows a

user to define up to 16 sine tones that can be laid on top of a background random test. Each tone can be either a

fixed frequency or a sweeping tone.

NOTE: Sine on random tests require convolution to be enabled, and therefore do not support multiple channels of

control.

Setting up a sine on random test

1. Make sure the software is in random mode.

2. Press the Test Setup button on the control panel.

3. The Random Control System Properties

panel is displayed.

4. Select the Sine On Random tab.

5. Enable the desired tones by selecting the

appropriate check boxes in front of each

tone.

6. For each tone:

a. If the tone is a harmonic of a previous

tone:

i Select the Harmonic of Tone

check box.

ii Select the harmonic relation of the

tone from the drop-down menu.

iii Select the tone that the current

tone is harmonically related to

from the drop-down menu. For

example, if Tone 1 sweeps from

100 to 150 Hz tone, setting Tone 2

to be a 2X harmonic of Tone 1

would cause Tone 2 to sweep

from 200 to 300 Hz at the same

rate as Tone 1.

b. To set up a new tone, select either a

Fixed Frequency or a Sweep tone. For more information on setting up a sine test, refer to “Section 3: Sine

Mode” later in this manual.

c. For a sweeping tone:

i Press the Sweep Options button to open the Sweeping Options setup panel.



ii Configure the Sweep Test as you

would a normal sine sweep test.

For additional information on

setting up a sine test, refer to

“Section 3: Sine Mode” later in this

manual.

iii To accept the displayed values,

press OK.

iv To close the panel without saving

any changes, press Cancel.

7. Once you have configured the sine on

random settings, you can run the test

exactly as you would a normal random test.

8. The sine tones will not start until the

background random test reaches its full

level. Test time will not begin counting until

the sine tones are within the tolerances set

for the random test.

NOTE: Multiple sine tones can be made to

sweep through each other using SOR.

During those intersections, there will be a

point when the amplitudes of the sine

waves are cumulative. This will cause much

more damage to a product that happens to

resonate at that frequency than if the sine

sweeps were run without crossing. In

general, crossing of SOR tones should be

avoided.



Running a sine on random test

When a sine on random test runs, it is similar to a standard random test but with the sine tone frequencies and level

displayed on the Control Response graph as illustrated below:

In the graph shown above, the relative amplitude of the sine tones is represented by small + signs in the upper part

of the graph. The 1st and 3

rd tones are harmonics of each other, the 2

nd and 4

th tones are unrelated. The strength of

the sine tones shown is relative to the random signal, and because pure sine tones do not represent well on a PSD

graph, and would otherwise interfere with the random signal control, they are stripped out of the random

background before processing. The sharp spikes at each tone are added post-processing to guide the eye.

NOTE: The presence of a pure sine tone affects at least three control lines on either side of the sine frequency. When

running stationary tones or slow sine sweeps, the effect of the sine tones can be minimized by adding more control

lines.



Random on random mode (optional)

The random on random feature of WinVCS 2 software is an option that can be purchased in addition to the standard

software. The random on random application works in conjunction with random mode. Random on random (ROR)

allows a user to combine a defined random test with a random on random table that defines a set of narrow band

random steps.

Random on random is often referred to as swept random on random. These tests define a wide band background test

combined with a set of narrow band steps. As the wide band test outputs a fixed random demand, the narrow band

slowly sweeps up and down within its specified frequency band. As it sweeps through the frequency band, each

narrow band step dramatically changes the amplitude level of the demand within the area that it is sweeping. The

software automatically adjusts the tolerance and abort limits to allow the test to continue without being stopped.

Setting up a random on random test

The Random on Random panel allows you to enter up to 16 narrow band steps for the test. NOTE: In addition to

defining the random on random table, you must define the background random test.

1. Make sure the software is in random mode.

2. Press the Test Setup button on the control panel.

3. The Random Control System Properties panel is displayed.

4. Select the Random on Random tab.

5. Check Enable Random On Random.

6. For each narrow band step:

a. In the Start (Hz) and Stop (Hz) fields,

enter the starting and ending

frequency in Hz. The start band and

stop band frequencies define the

range of frequencies that the filter for

the narrow band step will center on.

b. In the g2/Hz field, enter the PSD level

for the step to reach. This defines the

PSD output of the narrow band step.

c. In the Bandwidth (Hz) field, enter the

bandwidth of the filter in Hz. The

bandwidth defines the width of the

narrow band filter.

d. In the Min/Sweep field, enter the

sweep speed in minutes per sweep.

The minutes per sweep defines how

long the band will take to sweep up or

down the assigned frequency range.






Running a random on random test

When a random on random test runs, it is similar to a standard random test, but with the narrow band steps

superimposed on a wide band on the Control Response graph as illustrated below:

NOTE: The WinVCS software will not allow the demand to transition from a narrow band to the lower broad band

random test faster than 4 dB/line. To make this transition steeper, add more control lines.



Shaker limits in random mode

The Force field displays the combined RMS force of the random, sine on random and random on random demands.

The warning box turns red when this number exceeds the random force rating of the shaker and yellow at 80% of the

random force rating.

The Velocity field displays three times the RMS velocity of the random test, including random on random, with the

velocity of any sine on random tones added on. The warning box turns red when this number exceeds the sine

velocity rating of the shaker and yellow at 80% of the sine velocity rating. This method is intended to protect the

system from excessive clipping due to amplifier voltage limitations.

By default, the Displacement field displays three times the RMS displacement of the random test, including random

on random, with the sine on random displacement added on. This three-sigma method is the standard way to

calculate random displacement and can be used to compare a test between controllers, but it is widely understood to

underestimate the probability of an overtravel abort. Whenever a random test is created or modified, WinVCS 2 runs a

statistical algorithm that incorporates the demand and test duration to estimate the expected single highest peak-to-

peak motion of the armature and to estimate the number of overtravels (if any) expected before test completion. This

number of overtravels is used for warning messages regardless of user settings.

To display the estimated highest peak-to-peak motion instead of

the conventional three-sigma limit:

1. Click the Config button. The Shaker Parameters dialog box

will open.

2. Under Random Displacement Limit Warning, select Highest

Expected Excursion.

3. The Displacement warning box turns red if the number it

displays exceeds the displacement rating of the shaker, and

yellow at 80% of the displacement rating or if at least one

overtravel is expected.

WinVCS 2 Instruction Manual Sine Mode


Section 3: Sine Mode

Sine mode allows you to define, edit, run, and view sine vibration tests. This section describes the sine mode graphs

and provides procedures for defining and editing sine mode tests. Special programming and operating techniques

are also described.

Sine mode graphs

The sine mode graphs display the defined test and the real-time closed loop displays during the test. The defined test

plots the desired response plot from the shaker. The real-time closed loop graphs show how the system is operating

to achieve the desired response.

Response

The control and monitor response graphs display the actual response from the control and monitor accelerometer(s)

mounted on the shaker. All control and monitor response graphs can also display the abort and tolerance limits.

There are three different control and monitor response graphs:

• The acceleration graphs plot the acceleration response over the defined frequency band.

• The velocity graphs plot the velocity response over the defined frequency band.

• The displacement graphs display the displacement over the defined frequency band.

NOTE: Velocity and displacement are calculated from the accelerometer signal. Anything that might corrupt the

fidelity of the accelerometer (such as temperature changes or going beyond its reliable frequency range) also corrupts

the corresponding velocity and displacement graphs.

Sine Mode WinVCS 2 Instruction Manual


Drive

The software plots the actual frequency-domain

drive signal output on the Drive graph. The graph

displays the amplitude of the drive signal’s voltage

over the defined frequency range. The software

converts this signal to a time-domain drive signal

that is applied to the shaker amplifier.

Transmissibility

The Transmissibility graph displays the response

ratio between the monitor and control

accelerometers. The software plots the monitor

response divided by the control response (in g’s)

across the defined frequency band.

This graph can be used to find a resonance point

on a product:

1. Place the monitor accelerometer on the

product where a resonance is expected to

occur.

2. Place the control accelerometer on the product

fixture near the product mounting point.

3. As a test is run, observe the ratio between the

product and the fixture. The resonance point is

the highest transmissibility peak between two channels.

When multiple monitor channels are shown, each one is compared to the control and displayed as its own line on the

graph.



Reference

The Reference graph displays the demand

acceleration plot over a defined frequency band.

You can define or edit the demand plot from the

Test Profile panel. The demand plot defines the

response the closed-loop system is working to

achieve during the test. The demand plot is

surrounded by two bands:

• The tolerance band is displayed as the two

lines closest to the demand plot. They display

the acceptable amplitude limits for the test.

• The abort band is displayed as the two outer

lines. They display the absolute amplitude

limits of the test. The test stops if the response

exceeds these limits.

Types of sine testing

There are three types of sine wave testing:

• Sweep: A product is vibrated at a range of frequencies for a specific amount of time.

• Fixed: A product is vibrated at a specific frequency, with a specific peak acceleration, for a specific amount of

time, such as 20 Hz at 2 g’s for 10 minutes.

• Resonance search and dwell: A sine sweep test is performed and once resonance is found, the product is

vibrated at that frequency for a specific amount of time.

Defining a new sweep test

The software provides a test definition wizard for each vibration mode. The sine mode wizard takes you sequentially

through the sine mode windows, allowing you to define a complete test. Once a test is defined, it is loaded into the

main window. You can also select Test Setup from the Options drop-down menu to define a new sine test.

1. Select the Sine Mode button on the toolbar.


3. The wizard loads and takes you through all the profile definition displays. The wizard allows you to define a

sweep sine test or a fixed sine test. The following paragraphs illustrate how to set up a sweep sine test. For fixed

sine tests, see “Defining a new fixed frequency or search and dwell test” later in this section.



Test Profile panel

The Test Profile panel allows you to set up the overall characteristics of a sweep sine test.

1. Select Sweep from the Test Type drop-

down menu. Sweep tests move the sine

wave up and down a defined frequency

range.

2. Select the Sweep Test characteristics:

a. From the Sweep Type drop-down

menu, select how the test sweeps

across the frequency band.

• To sweep the signal up and down

across the frequency range, select

Bi-Directional.

• To sweep from the starting

frequency to the highest

frequency and then begin a new

sweep from the lowest to the

highest frequency, select Up.

• To sweep from the starting

frequency to the lowest frequency

and then begin a new sweep from

the highest to the lowest

frequency, select Down.

b. In the Start Freq field, enter the

starting frequency. The drive signal is

brought up to level at this frequency

and continues normally from there.

c. For bi-directional tests, select the starting direction from the Start Direction drop-down menu.

3. Select the Sweep/Search test options:

a. From the Sweep Start drop-down menu, select the start mode.

• To begin sweeping as soon as the response is up to the level, select Automatic.

• To bring the drive up at the starting frequency and then go into hold status, select Manual. Press the

Run or Resume button on the control panel to begin the manual sweep.

b. From the Sweep Rate drop-down menu, select the sweep rate.

• To enable the Logarithmic Rate oct/min field, select Octave. Enter how many octaves the test will

sweep through per minute.

• To enable the Logarithmic Rate dec/min field, select Decade. Enter how many decades the test will

sweep through per minute.

• To enable the Linear Rate field, select Linear. Enter how many hertz the test will sweep through per

second.

• To have the controlled calculate a sweep rate from a specified time, check the Sweep Time box and

enter a time.

NOTE: Once you enter a value, the software calculates the value for the other two fields so that the sweep

time for one cycle is the same for each sweep type.



4. Select the Abort Parameters:

a. In the Peak Output field, enter the maximum peak output voltage for the drive signal. If the peak voltage

ever exceeds this value during a sine test, the test stops.

b. In the Start Peak Output field, enter the maximum peak output voltage the drive signal can achieve before

the test comes to level. This value is also used at the beginning of a test to check for an open loop condition.

As the drive signal develops, the software checks for a response from the shaker. If it looks like the drive

signal will exceed the Start Peak Output value before a large enough response from the accelerometers is

detected, an open loop abort occurs.




• Minimum uses the lowest signal.

• Maximum uses the largest signal.

• Average uses an average of all of the signals.





panel is only available when a Thermotron machine controller interface cable is used.


a. If automatic gain control is not

enabled, check the Use Preset Gain

check box and enter the preset gain

value.



preset field. NOTE: This allows gain and

field settings to be saved per test.




For information on enabling power savings, refer

to “Power savings” in Section 1 of this manual.



Segments panel

The Segments panel defines the demand plot for the test. The demand plot sets the parameters for the desired

response from the shaker. The drive output signal to the shaker amplifier is developed based on this plot. The drive

outputs signal is modified to maintain a control response that is within the tolerance limits. NOTE: The table

automatically re-sorts by frequency.

1. The Seg # column lists the frequency

segment. The frequency segment is a

defined portion of the frequency band

between breakpoints. Each segment starts

at the frequency where the preceding

segment ended.

2. In the Start Hz and Stop Hz fields, enter

the desired starting and stopping

frequencies. These fields define the

breakpoints within the frequency band.

NOTE: The Start Hz field of the first

segment and the Stop Hz of the last

segment define the overall bandwidth of

the test. Any frequencies between the first

segment’s Start Hz and the last segment’s

Stop Hz that are left at zero are

automatically calculated based on the

Level, Slope To, and Ctrl Type fields.

a. Enter the Start Hz for segment 1.

b. Enter the Stop Hz for the final

segment. NOTE: The Start Hz and

Stop Hz values define the frequency

limits of the test.

c. Enter a value of zero into all of the other Start Hz and Stop Hz fields.

d. When you finish defining a test, press OK.

e. When you open the test again, all of the calculated frequency breakpoints will be displayed in the table.

3. Enter the desired number of units (G pk, in/s, or in p-p) of the type of control into the Level field. Leave the

Slope To field zero.

4. To enable sloped acceleration, change the value of the Slope To column to any value other than the value in the

Level column. This segment of the sine test ramps from the Level value to the Slope To value over the course of

sweeping the segment’s frequency range. In the image above, the G level will ramp from 3 to 6 G over the

frequency range of 20 to 2,000 Hz.

5. Select the desired type of control from the Ctrl Type drop-down menu. You can select Acceleration, Velocity, or

Displacement. The Ctrl Type, Level, and Slope To values allow you to define the control applied to each

segment.

6. In the Cmp field, enter a value to define how fast to react to a change in response. This value defines how often

the drive is adjusted and adjusts the drive output to stay within the control limits. The range is 0.1 to 100.

7. The Reference Preview displays a small graph of the values selected in the Segments table.





Control Limits panel

The Control Limits panel defines how far the control input channels’ response can deviate from the demand plot.

NOTE: The table automatically re-sorts by frequency. Enter all tolerance and abort values in positive units dB.







limit above the demand plot.


limit below the demand plot.


within the tolerance limits before the test

clock starts. Once the clock starts, the

software issues a warning any time the

control response exceeds a tolerance limit.

4. In the Abort +dB field, enter the abort


clock starts, the software stops the test any

time the control response crosses the limit.

5. In the Abort -dB field, enter the abort limit

below the demand plot. Once the clock


the control response crosses the limit.





Monitor Limits panel

The Monitor Limits panel defines how far the monitor-input channels’ response can deviate from the demand plot.

NOTE: The table automatically re-sorts by frequency. Enter all tolerance and abort values in positive dB units.


Disable Monitor Limits check box at the

bottom of the Monitor Limits panel.


monitor limits.










limit.


limit below the demand plot. Once the



limit.

5. In the Abort +dB field, enter the abort limit

above the demand plot. Once the clock


the monitor response crosses the limit.


test any time the monitor response crosses the limit.








1. Enter the duration of the level by entering

a value in either the Test Time field or the

# Sweeps field. If both are specified, the

# Sweeps field is used and Test Time will

not begin counting until the control

response is within tolerance and the

frequency sweep has begun. A Sweep is

defined as one pass that reaches an

endpoint.

For example, to make a Bi-Directional test

start at its Start Freq., sweep to its highest

frequency, and then sweep to its lowest

frequency, the # Sweeps field should be

set to 2.

2. The fields in the next two columns adjust

the level of the demand plot’s output






value.



software will run the test.

• In the % Level field, enter the percent of the demand profile that the software will output.





Defining a new fixed frequency or search and dwell test

The software provides a test definition wizard for each vibration mode. The sine mode wizard takes you sequentially

through the sine mode windows, allowing you to define a complete test. Once a test is defined, it is loaded into the

main window. You can also select Test Setup from the Options drop-down menu to define a new sine test.

1. Select the Sine Mode button on the toolbar.


3. The wizard loads and takes you through all the profile definition displays. The wizard allows you to

define a sweep sine test or a fixed sine test. The following paragraphs illustrate how to set up a fixed sine or

search and dwell test. For sweep sine tests, see “Defining a new sweep test” earlier in this section.

Test Profile panel

The Test Profile panel allows you to set up the overall characteristics of the test.

1. Select Fixed from the Test Type drop-

down menu. Fixed tests maintain a sine

wave at a defined frequency.

2. In the Fixed Freq field, enter the frequency

of the sine wave. Make sure the frequency

is within the specifications of your shaker.

3. Select the type of control to use from the

Control Type drop-down menu. During

the test, this parameter is controlled at a

fixed level and the other two parameters

are calculated from this value.

4. In the Fixed Control field, enter the control

value using these scales:

• G peak (Acceleration)

• In/s (Velocity)

• Inches peak to peak (Displacement)

5. In the Compression field, enter a value to

define how fast to react to a change in

response. This value defines how often the

drive signal is adjusted and adjusts the

drive output signal to stay within the

control limits. The range is 0.1 to 100.

6. If needed, configure the Search & Dwell options:

• Select Off to enable standard fixed testing.

• Select On to enable the optional resonance search and dwell test. For more details, see “Resonance search

and dwell tests” later in this section.

• If you are running a resonance search and dwell test, enter the low frequency limit of the search in the Low

Freq. Limit field, and enter the high frequency limit of the search in the High Freq. Limit field.



7. Select the Abort Parameters:

a. In the Peak Output field, enter the maximum peak output voltage for the drive signal. If the peak voltage

ever exceeds this value during a sine test, the test stops.

b. In the Start Peak Output field, enter the maximum peak output voltage the drive signal can achieve before

the test comes to level. This value is also used at the beginning of a test to check for an open loop condition.

As the drive signal develops, the software checks for a response from the shaker. If it looks like the drive

signal will exceed the Start Peak Output value before a large enough response from the accelerometers is

detected, an open loop abort occurs.




• Minimum uses the lowest signal.

• Maximum uses the largest signal.

• Average uses an average of all of the signals.










value.










manual.



Limits panel

The Limits panel defines how far the control and monitor response signals can deviate from the demand plot. NOTE:

Enter all values in positive dB units.


Disable Monitor Limits check box.


monitor limits.




2. Enter the following control limits and

monitor limits (if enabled):

a. In the Max Tolerance fields, enter the

tolerance limit above the demand plot.

Once the clock starts, the software

issues a warning any time the

response exceeds the limit.

b. In the Min Tolerance fields, enter the

tolerance limit below the demand plot.


issues a warning any time the

response exceeds the limit.

c. In the Max Abort fields, enter the

abort limit above the demand plot.


stops the test any time the response crosses the limit.

d. In the Min Abort fields, enter the abort limit below the demand plot. Once the clock starts, the software

stops the test any time the response crosses the limit.

NOTE: Program the monitor limits to allow greater deviations from the demand plot than the control limits,

because the software will not adjust its output to compensate if the monitor channel response deviates

outside the monitor limits. If tighter limits on the monitor channels are programmed, the test could stop

before the control response indicates an out-of-tolerance condition.








1. In the Test Time field, enter the duration of

the level. Once the control response is

within the tolerance limits of the test, the

software starts the test clock based on this

value.

NOTE: The # Sweeps field does not apply

to fixed tests. To run a resonance search

and dwell test, the # Sweeps field must be

set to zero.

2. The fields in the next three columns adjust

the level of the demand plot’s output






value.



software will run the test.

• In the % Level field, enter the percent

of the demand profile that the software

will output.






Once a test is defined it can be modified to meet

changing test needs. A new test can also be created from

a pre-existing test. A test can be edited in any operating

state (run, stop, or hold). This allows you to edit the test

and watch the results of your changes. However, any

change to a control parameter while the test is running

will cause it to re-equalize. This resets the timer on the

current level, if a Test Time is being used.


2. Press Test Setup on the control panel, or select Test

Setup from the Options drop-down menu.

3. Select the desired tab to bring the panel to the

front.

4. Edit the parameters as described in “Defining a new

sweep test” earlier in this section.



7. To close the panel without saving any changes,

press Cancel.

8. To save the test under its original name, press the

Save button. To save the test under a new name, select Save As from the File drop-down menu.

Graphing an armature response plot

An armature response plot graphs the characteristics of the armature as the drive passes through the shaker’s

frequency band. The armature response plot can be used to compare the performance of an armature over time.

Perform an armature response to see how the armature responds normally. Then, if the shaker begins to experience a

loss of performance, re-plot the armature response and compare it to the original response. If the two plots are

dramatically different, damage may have occurred on or around the armature. NOTE: This procedure can also be used

to monitor the performance of a fixture over time. Be sure to record the accelerometer mounting location with the

baseline test results.

1. Install the channel 1 accelerometer in one of these two locations:

• For 16” and 24” armatures, install the accelerometer on one of the UNC bolts in the 16” diameter pattern.

• For 12” armatures, install the accelerometer on one of the UNC bolts in the 12” diameter pattern.

2. Set up a sine test with the following parameters:

a. On the Test Profile panel, enter the following parameters:

Test Type Sweep

Sweep Type Bi-Directional

Start Freq 200.00 Hz

Start Direction Increasing

Sweep Start Manual

Sweep Rate Octave

Logarithmic Rate 1 oct/min

Peak Output 6 Volts

Start Peak Output 2 Volts

Control Channels Channel 1 only



b. On the Segments panel, define one segment with the following parameters:

Start Hz 20.00

Stop Hz 2,000.00 (3,000.00 for DS-2000 and all DSX shakers)

Level 3.0 g’s (29.4 m/s2) peak

Ctrl Type Acceleration

Cmp 1.5

c. On the Level Schedule panel, enter one level with the following parameters:

Test Time 00:00:00

# Sweeps 2

dB Level 0.00

% Level 100

3. Set up the Control Acceleration graph with these properties or use Auto-scale:

X and Y Axis Scales Log

X Axis Minimum 10.00 Hz

X Axis Maximum 2,000 Hz (3,000 Hz for DS-2000 and all DSX shakers)

Y Axis Minimum 1 G pk

Y Axis Maximum 10 G pk

4. Click Data & Reports on the menu bar and select Report Generation Setup. On the Data and Report Options

panel, check the Auto Save Data check box.

5. From the Options drop-down menu, select Fixed Output Drive. A check mark indicates that the output drive is

set at a fixed voltage.

6. Run the test. The test should start up at 200 Hz and then go into hold.

7. Press Run once the response stabilizes.

8. Display the Control Acceleration graph. The signal should sweep down to 20 Hz, sweep up to 2,000 (or 3,000)

Hz, and then stop.

9. Print the Control Acceleration graph.

10. The plot is now stored under the file name of your test, followed by a three-digit extension.

11. Once you finish running the test, go into the Options menu and remove the check mark from the Fixed Output

Drive command.



Swept sine step change tests

The WinVCS 2 software requires special programming procedures to perform a swept sine step change test. During a

swept sine test, the software changes acceleration levels almost instantaneously. This can cause the test to abort when

the response input from the shaker changes more slowly than the abort lines. The tolerance and abort limits need to

be open enough to prevent the test from aborting.

A swept sine step change test programs one or more step changes in the acceleration somewhere in the middle of

the sweep. A step change shifts the demand from one acceleration level to another while at the same frequency.

This figure shows a basic step

change entry from the Segments

panel. This figure shows a step

change at 50 Hz.

1. Seg # 1 sets acceleration at 2.5 acceleration peak between 5 Hz and 50 Hz.

2. Seg # 2 drops the acceleration to 1.2 acceleration peak between 50 Hz and 150 Hz. The step is at 50 Hz.

During this step change, the software drops the peak demand to a lower level. If the limits are programmed

incorrectly, they drop immediately as well. With the limits set at a constant 3 dB and 6 dB, the limits change with the

acceleration. No matter which sweep direction the signal is heading, the acceleration response signals change more

slowly. The slower change causes the response signals to cross the abort lines and abort the test. To adjust for the

slower analog response signal from the shaker, you must adjust the Control Limits panel. As shown in the graphs on

page 3-17 and 3-18, the adjustment serves two purposes:

• It moves the tolerance and abort limits enough to allow for the slower response signal.

• It provides a more readable graph.

Setting up a swept sine step change test

1. Use this formula to find the difference

(x dB) between the two acceleration

peak outputs (N1 & N2):

|20 Log (N1/N2)| = x dB

a. For example, if two acceleration

control values are 2.5 and 1.2, the

difference would be the following

formula:

|20 Log (2.5/1.2)| = 6.3752 dB

b. Use the x dB value (rounded to

the nearest tenth) to adjust the dB

levels (in this example, 6.4 dB).



2. Determine how far up and down the frequency band you need to move your limits to adjust for the response,

establishing a frequency bandwidth through which the analog response signal is allowed to sweep:

a. To adjust the limits, try different limits and watch the Reference Preview graph. The object is to find limits

that allow for the shaker’s response time while providing adequate signal limits. Five frequency breakpoints

are needed: two for the abort limits, two for the tolerance limits, and one for the demand.

Segments

Control Limits

b. In the illustration above, the limits from the Control Limits panel are adjusted by 10 Hz each.

• Abort -dB drops 20 Hz early at 30 Hz, followed by Tol -dB at 40 Hz.

• The demand falls in the middle at 50 Hz.

• Tol +dB drops 10 Hz late at 60 Hz, followed by Abort +dB at 70 Hz.

3. Insert the five frequencies determined in step 2 as five sequential breakpoint lines. Start with the lowest

frequency and continue sequentially to the highest frequency. The five frequencies are inserted between the

original breakpoint lines.

4. Use the difference found in step 1 to program the five frequency breakpoints:

a. Add the difference to Abort -dB on the first frequency.

b. Add the difference to Tol -dB and Abort -dB on the second frequency breakpoint.

c. Add the difference to Tol +dB and Abort +dB on the third frequency breakpoint. (The third breakpoint

occurs at the step change frequency.) Return the Tol -dB and Abort -dB to their normal levels (for example,

3 dB and 6 dB).

d. Return Tol +dB to its normal level on the fourth frequency breakpoint. Add the difference to Abort +dB.

Accelerometer Responseon Increasing Sweep

Accelerometer Responseon Decreasing Sweep

Abort +dB

Tol +dB

+2.5 peak

Tol -dB

Abort -dB

Abort +dB

Tol +dB

+1.2 peak

Tol -dB

Abort -dB



Segments

Control Limits

e. Return all values to their normal limits on the fifth column.

5. Run the test. The only value that may need adjusting is the breakpoint frequencies. If the test aborts at

breakpoint, widen the bandwidth determined in step 2. If the frequencies are too wide, narrow the bandwidth.

Abort +dB

Tol +dB

+2.5 peak

Tol -dB

Abort -dB

Abort +dB

Tol +dB

+1.2 peak

Tol -dB

Abort -dB

Abort +dB at 70 Hz

Tol +dB at 60 Hz

Tol -dB at 60 Hz

Abort -dB at 70 Hz



Resonance search and dwell tests

The resonance search and dwell (RSD) option allows the software to find the resonant frequency of a product load

and dwell at that frequency using a fixed sine wave test. This test allows products to be tested at their resonant

frequencies to determine if there are defective areas and/or to observe how products react.

RSD compares the control channel to the monitor channel to detect the highest transmissibility peak between the two

channels. Normally, the two channels maintain a constant transmissibility. When the test sweeps through a resonant

frequency, the transmissibility peaks between the two channels. When a resonant frequency is identified, the test

dwells at that point, adjusting the frequency as necessary to keep the sine wave right on the resonance.

Setting up a resonance search and dwell test

1. Place the accelerometers in the following positions:

• Place the control accelerometer on a rigid part of the product or fixture and connect it to the Channel 1

input.

• Place the monitor accelerometer on the product where you expect the resonance to occur and connect it to

the Channel 2 input.

2. Run a sweep test on the product to determine where resonance occurs:

a. Use the default sweep test provided with the software.

i) From the File drop-down menu, select Open Existing Test.

ii) Select Sine Sweep.vcs.

b. From the Options menu, select Test Setup and make the following changes:

i) On the Test Profile panel, change the Monitor Channel to 2.

ii) On the Segments panel, set the control values of the sweep to the level that your dwell test will run. If

you have to run the sweep at a different level, remember the resonant frequency may shift as the level

changes. This means that the dwell test may need to be set to search for the resonant frequency

through a wider frequency range.

iii) Select OK to load the changes.

c. Run the test.

d. Use either the Transmissibility or the Monitor Acceleration graph to view the sweep test.

e. Use the cursors to locate the frequency where each resonance occurs. Snap to peak is helpful for this.

f. While the test is running, watch the monitor channel’s acceleration levels. By default, the monitor channel’s

acceleration must be less than four times the control channel’s acceleration.

g. Once you have documented the resonant frequencies, stop the test.



3. To run the resonance search and dwell test:

a. Press the New Test icon, select New

Test from the File drop-down menu,

or press Ctrl+N.

b. From the Test Type drop-down menu,

select Fixed.

c. From the Search & Dwell drop-down

menu, select Ch. 2.

d. Set the Low Freq. Limit and High

Freq. Limit values to the frequency

range of your search. NOTE: The range

should be as narrow as possible, yet

wide enough to compensate for any

shift in the resonant frequency.

However, a wide range will cause the

search portion of the test to get very

long.

e. Select Control Channel 1 and

Monitor Channel 2.

f. Press Next to view and edit the Amp

Control panel.

g. Press Next to view the Limits panel

and set the limits to the normal

settings of your test.

h. Press Next to view and edit the Level Schedule panel. Set the Test Time field to the desired duration of the

dwell and the # Sweeps field to zero.

i. Press Finish to return to the main window.

j. To begin the test, press Run on the control panel.

k. Once the resonant frequency is found:

i The software automatically enters the resonant frequency into the Fixed Freq field.

ii The dwell portion of the test begins immediately. Subsequent tests may be run at that frequency

without the search portion by selecting Off from the Search & Dwell drop-down menu.



Running a search and dwell test

When a search and dwell test runs, it sweeps through the range provided by the frequency limits until the resonant

frequency is located. Once the frequency is located, the software locks onto the resonance and dwells at that

frequency. The resonant frequency is also loaded into the Fixed Freq field of the Test Profile panel.



Finding the resonant frequencies by touch

WARNING: The shaker’s conducting flexures and welding cables carry live currents that can kill. Make sure

that the shaker’s thermal shield and armature insulation are in place, covering the flexures before operating

the shaker.

WARNING: Use extreme caution when working with a live product load. Electrical shock can kill.

WARNING: Use double ear protection (earplugs and muffs) and wear safety glasses when working around an

operating shaker.

If it is difficult to achieve a successful resonance dwell, the accelerometers may not be positioned properly:

1. Place the control accelerometer on a rigid part of the product or fixture.

2. Place the monitor accelerometer on the area of the product where you suspect the resonance will occur.

3. Run a standard sweep test, and watch the Monitor Acceleration graph.

4. As the test sweeps though the frequencies where resonance is occurring, touch the product to find the locations

where the most severe vibration is occurring. You should be able to feel where the resonance is the greatest.

5. Stop the test, and move the monitor accelerometer to the part of the product where you felt the greatest

resonance.

6. Run the sweep and RSD tests as described previously.

Defining swept sine dwelling

The swept sine dwelling feature allows a sweeping sine test to dwell at defined frequencies during the sweep for a

specified time, and then continue with the sweep.

To the right is the Segments panel, which

details the different sections of a sweeping sine

test. The Dwell parameter defines how long

that segment will dwell at the defined Stop Hz

frequency. When running, the test will pause at

these frequencies when sweeping in each

direction.

Note that if a dwell is defined for the final

segment in a test, the dwell will occur just once,

at the end of an up sweep, and not be repeated

immediately afterwards when sweeping down.

When a sweep is paused to dwell, a note will be

made in the log file of the time and frequency,

and then a note will be made when the test is

resumed:

4/21,14:57:00 Sine sweep dwelling at 30.72 Hz

4/21,15:02:00 Sine sweep resumed

If something, such as an abort, were to occur

during a dwell, it will be clear under what

conditions it occurred.



Shaker limits in sine mode

The Force field displays the peak force of the sine demand. The warning box turns red when this number exceeds the

sine force rating of the shaker and yellow at 80% of the sine force rating.

The Velocity field displays the peak velocity of the sine demand. The warning box turns red when this number

exceeds the sine velocity rating of the shaker and yellow at 80% of the sine velocity rating.

The Displacement field displays the peak displacement of the sine demand. The warning box turns red when this

number exceeds the shaker’s displacement rating and yellow at 80% of the shaker’s displacement rating.

WinVCS 2 Instruction Manual Shock Mode


Section 4: Shock Mode

Shock mode allows you to define, edit, run, and view shock tests. This section describes the shock mode graphs and

provides procedures for defining and editing shock tests. Special programming and operating techniques are also

described.

Shock mode graphs

The shock mode graphs display the defined test and the real-time closed loop displays during the test. The defined

test plots the desired response plot from the shaker. The real-time closed loop graphs show how the system is

operating to achieve the desired response.

Acceleration

The Acceleration graph displays the programmed

demand plot, tolerance and abort limits, as well as

the response plot. Acceleration is plotted as a

function of time.

When a test is running, the response plot is

displayed as the current shock pulse on the graph.

The response plot is updated each time a new

shock pulse is input from the control accelerometer.

Velocity

The Velocity graph displays the velocity of the

shock pulse as a function of time. When a test is

running, the velocity of the shock pulse response is

plotted on the graph for comparison with the

reference.

Shock Mode WinVCS 2 Instruction Manual


Displacement

The Displacement graph displays the displacement

of the shock pulse as a function of time. When a

test is running, the displacement of the shock pulse

response is plotted on the graph for comparison

with the reference.

Drive

The Drive graph displays the drive applied to the

shaker by the vibration control system as a function

of time.

SRS Analysis (optional)

On systems with the optional SRS package, the SRS

Analysis graph displays the Shock Response

Spectrum of the shock pulse for simple damped

oscillators as a function of undamped natural

frequency. When a test is running, the SRS of the

most recent shock pulse is plotted on the graph for

comparison with the reference.



Defining a new shock test

The software provides a test definition wizard for each vibration mode. The shock mode wizard takes you sequentially

through the shock mode windows, allowing you to define a complete test. Once a test is defined, it is loaded into the

main window. You can also select Test Setup from the Options drop-down menu to define a new shock test.

1. Select the Shock Mode button on the toolbar.





Test Define panel

The Test Define panel allows you to set up the overall makeup of the test.

1. To define a classic shock test, select Classic

from the Pulse Type drop-down menu.

2. In the Pulse Peak field, enter the peak

acceleration for the shock pulse.

3. In the Pulse Width field, enter the duration

of the pulse in milliseconds.

4. From the Waveform drop-down menu,

select the basic shape of the pulse. You can

select Half Sine, Triangle, Rectangle, Init

Sawtooth, or Term Sawtooth.

5. In the Pre/Post Type section, select

Adaptive or Historical pre/post pulses.

• The Adaptive selection will construct

pre/post pulses to make the most of

the shaker’s capabilities. You can select

MIL-STD-801F, IEC 60068-2-27 or

enter a Custom specification.

• The Historical selection gives access

to fixed types of pulse compensation

which have been used in the past. You

can select Simple, MIL-STD 810, MIL-

STD 810 (low g), Simple (810 Limits),

IEC 60068-2-27, or IEC 60068-2-27

(low g).

NOTE: For more information on the

Pre/Post Type options, see “Pre- and post-

pulse compensation options” later in this

section.

6. When a Historical Simple pulse is selected, the Pre/Post-Pulse field can be used to enter the percentage of the

full peak acceleration for the pre-pulse and post-pulse. These pulses combine to return the armature to zero

acceleration, velocity, and displacement after the shock pulse.

• If you increase this value, the acceleration of both pulses increases and their pulse widths decrease.

• If you decrease this value, the acceleration of both pulses decreases and their pulse widths increase.



7. When a Custom Adaptive pulse is selected, the Pre-Pulse, Pulse, and Post-Pulse fields can be used to enter

limits for their respective regions as a percentage of the full peak acceleration. The Adaptive shock algorithm will

then construct a reference to stay within those limits.

8. From the Pulse Polarity drop-down menu, select the direction of the acceleration pulse.

9. In the Inter Pulse Delay field, enter the number of seconds between pulses. NOTE: 0.25 seconds is the minimum

value.

10. Select the Control Channel and Monitor Channels to use by checking the appropriate check boxes. NOTE: You

can select only one control channel.










value.










manual. NOTE: Beginning with version 2.90,

Enable Power Savings is not available in shock

mode.



Test Limits panel

The Test Limits panel allows you to define performance limits of the test. NOTE: Enter all tolerance and abort values

in positive units % pk.

1. In the + Tolerance field, enter the

tolerance limit above the reference plot as

a percentage of acceleration peak.

2. In the - Tolerance field, enter the tolerance

limit below the reference plot as a

percentage of acceleration peak.

NOTE: The response acceleration must

stabilize between these limits before the

pulse quantity count starts. A warning is

displayed any time the acceleration

response plot crosses a limit. These limits

may be superseded by limits defined within

the Test Define panel.

3. In the Start Limit field, enter the maximum

drive signal output allowed during the start

of the test. If the drive signal exceeds this

value during start-up, the test is stopped.

NOTE: The NI-DAQ card is unable to send

out voltages in excess of ±10 V.

4. In the + Abort field, enter the abort limit

above the reference as a percentage of

acceleration peak.

5. In the - Abort field, enter the abort limit

below the reference plot as a percentage of

acceleration peak.

NOTE: Once a test begins, if the

acceleration response plot crosses either

Abort limit the test is stopped.

6. In the Run Limit field, enter the maximum drive signal output allowed during test operations. If the drive signal

exceeds this value, the test is stopped. NOTE: The NI-DAQ card is unable to send out voltages in excess of ±10 V.








1. In the Pulse Qty field, enter how many

times to repeat the pulse before the test

moves to the next level.

2. In the dB Level field, enter the number of

dB’s the test will run above or below the full

level of the test.

3. In the % Level field, enter the percentage

of the full test to output. NOTE: The dB

Level field must be set to zero to use this

field. Negative pulses cannot be entered

here. To alternate between positive and

negative pulses, use a Test Schedule.







Once a test is defined it can be modified to meet changing test needs. A new test can also be created from a pre-

existing test. A test can be edited in any operating state (run, stop, or hold). However, any change to a test definition

parameter will cause the test to abort. Changes to other parameters will reset the pulse counter for the current level.


2. Select Test Setup from the Options drop-

down menu.

3. Select the desired tab to bring the panel to

the front.

4. Edit the parameters as described in

“Defining a new shock test” earlier in this

section.





8. To save the test under its original name,

press the Save button. To save the test

under a new name, select Save As from the

File drop-down menu.



Shock response spectrum (optional)

The shock response spectrum (SRS) feature of WinVCS 2 is an option that can be purchased in addition to the

standard software. The shock response spectrum application works in conjunction with shock mode and requires the

shock option to be enabled as well. Shock response spectrum allows the user to generate a shock pulse that conforms

to a predefined shock response spectrum, and also analyze any classic shock pulse using SRS analysis.

Setting up an SRS test

1. Select the Shock Mode button on the toolbar.


3. The Shock Control System Properties

panel is displayed.

4. To define an SRS test, select SRS from the

Pulse Type drop-down menu. When SRS is

selected, the SRS Pulse Options become

enabled.

5. The Frequency/Accel (G) table defines the

shape of the SRS profile. This definition is

typically what is given as part of a test

specification. Each Frequency/Accel pair

defines a point on the spectrum.

6. In the Pulse Length field, enter the length

of the pulse in milliseconds. Pulses can be

from twice the period of the lowest

specified Frequency up to 1,000 ms. For

example, a 10 Hz sine wave has a period of

100 msec, so the depicted test must have at

least a 200 ms Pulse Length.

7. From the Octave Spacing drop-down

menu, select the desired octave spacing.

This parameter defines how many sine

waves are used as components of the final

pulse (or, when doing analysis, how many

sine waves are used for analyzing the

signal). The choices are 1/3, 1/6 and 1/12.

If 1/12 is selected, 12 damped sine waves

are generated for every octave in the profile

definition. NOTE: 1/12 octave spacing takes

more time to process than 1/3, but provides

better coverage of the spectrum.

8. In the Q field, enter the desired quality value. The Q or Quality value defines how quickly the sine waves decay.

NOTE: The damping ratio can be calculated by Q21=ζ , so a Q of 10 implies a damping ratio of 0.05 (or 5%).

9. To set a tolerance value, click the Tolerance check box and enter a value in the dB field.

10. From the Select Waveform Type drop-down menu, select the desired waveform type. There are two different

methods for generating the SRS pulse: Random (which is the default) and Reverse Sine Sweep. Each method

uses random number generation to approximate the given SRS profile as closely as possible. Reverse Sine

Sweep tends to concentrate higher frequencies at the beginning of the pulse, giving a more traditional waveform

with a burst followed by reverberation.



11. To cause the software to attempt to generate

a pulse that matches the test definition more

exactly, press the Refine Pulse button. The

dialog box to the right will be displayed.

When a better pulse is found, it will return to the main setup screen. The process can be stopped at any time by

pressing the Stop Now button. If it takes an exceptionally long time, it is possible that the pulse already in use is

closely matched to the given test definition.

12. To generate a new pulse regardless of whether or not it is “better” than the currently used pulse, press the Reset

button.

Running an SRS test

CAUTION: Before running an SRS test, double check the Peak Ref (G), Vel Ref (in/s), and Disp Ref (in) displays

(the right hand column of three values on the status panel) to ensure they are within the limits of your shaker.

When an SRS test runs it is similar to a classic shock test: a defined number of pulses over one or more test levels.

NOTE: If the control accelerometer deviates from the defined profile by more than the amount specified in the Test

Limits while an SRS test is running, the test will abort. The offending section of the response that failed will be

highlighted in red.



SRS analysis

Systems with SRS enabled have the ability to analyze any shock test with SRS. This can be useful for looking at

monitor accelerometers mounted on a product during test. The Octave Spacing and Q value outlined above define

how the SRS analysis is performed.



Pre- and post-pulse compensation options

The goal of pre- and post-pulse compensation is to create conditions such that the sharp uni-directional acceleration

of the pulse can be delivered to the armature without exceeding the limits of the shaker system, and to bring the

armature to rest in its starting position afterward. The Pre/Post Type option makes available some standards for

defining the test limits that conform to commonly required standards:

1. Simple: This Historical pulse compensation

uses a simple half-sine waveform for the pre-

and post-pulse shapes. The magnitude of the

pre- and post-pulse is defined by the Pre/Post

Pulse percentage setting. The smaller the

percentage, the longer the pulses have to be to

provide adequate compensation. This is the

default mode of operation for previous versions

of WinVCS.

2. MIL-STD-810F: The MIL-STD-810F shock

testing standards restrict the G level of the pre-

pulse to within ±5% of the magnitude of the

pulse, and the post pulse to +20/-30%.

Thermotron Historical MIL-STD-810F and

MIL-STD-810F (low g) references are available

for Half Sine, Init Sawtooth, and Term

Sawtooth waveforms.



MIL-STD-810 strictly limits how far a classic shock pulse may deviate from the defined ideal pulse shape. To

define these limits, the pulse is divided into three sections: pre-pulse, the pulse itself, and post-pulse.

Historical MIL-STD-810 30 g, 11 ms pulse with limits

• For pre-pulse, the acceleration level must not exceed ±0.05 of the peak g level of the test, until it is within

0.3D (where D is the duration of the pulse) of the main pulse, where the limits ramp up to 0.2 times the

pulse’s level.

• During the main pulse, the high limit is defined as 1.15 times the amplitude of the pulse, and the low limit is

defined as 0.85 times the amplitude of the pulse.

• For post-pulse, the high limit is 0.2 of the pulse’s peak, and the low limit is 0.3 of the pulse’s peak.

3. Simple (810 Limits): A hybrid of the above two pre/post types, this uses the Simple method of generating the

shape of the pre- and post-pulses, but the MIL-STD-810 standards for checking the limits (and thus validity) of

the test. This requires that the Pre/Post-Pulse setting be less than 5% so that it fulfills the MIL-STD-810

specification. This solution works well for very high g level, short pulses (such as 100g, 1.5ms) that do not need to

optimize displacement usage.

4. IEC 60068-2-27: Designed to conform to the IEC 60068-2-27 and 60068-2-29 specifications, which limit the pre-

and post-pulse to ± 20%. It is easier to optimize displacement within the IEC 60068-2-27 specification than the

MIL-STD-810F pulse. Thermotron Historical IEC 60068 and IEC 60068 (low g) references are available for Half

Sine, Init Sawtooth, and Term Sawtooth waveforms. NOTE: MIL-STD-810G adopted the IEC 60068-2-27 pre-

and post-pulse limits.

Pre-pulse

Pulse

Post-pulse



Adaptive pre- and post-pulse compensation

Newly created shock tests default to the Adaptive pre/post method. Rather than stretch a fixed reference to fit the

pulse specifications, Adaptive shocks are built by a kinematics solver within the WinVCS software to match the pulse

requirements to the capabilities of the shaker. For pulse specifications well within the shaker’s capabilities, the

Adaptive method will result in somewhat higher displacement and more noise margin than the Historical references.

However the Adaptive method is also capable of running higher G levels than any of the Historical references for a

given specification.

Within the Adaptive method, selections can be made for MIL-STD-810F, IEC 60068-2-27, or Custom specifications.

If Custom is selected, the Pre-Pulse, Pulse and Post-Pulse boxes will activate allowing one to modify the tolerances

in each of those areas separately. These percentages are expressed relative to the peak pulse acceleration. For

example, to duplicate the IEC 60068-2-27 specification, all three boxes would be set to 20%. All Adaptive

specifications are available for all five of the classic shock waveforms (Half Sine, Triangle, Rectangle, Init Sawtooth,

and Term Sawtooth).

NOTE: MIL-STD-810 and IEC 60068-2-27 construct sawtooth pulses slightly differently. (The IEC specification does

not have a perfectly vertical edge and therefore has less high frequency content.) The Adaptive reference builder

uses the sawtooth reference from the specification that was most recently selected.

Shock pulse reference filter options

The Frequency limits and filtering options on the Test Limits panel apply to Classic shock pulses only, not SRS

pulses, and should be considered advanced settings. For most tests, the defaults will work best.

• Cutoff Frequency: The controller will only

attempt to control frequency components of

the pulse up to the given frequency (in Hz). The

default of 3,333 Hz is chosen in order to cover

the capabilities of most shakers.

• Filter Reference Pulse: This option, enabled by

default, applies a phase-invariant 4-pole low-

pass filter to the reference pulse with its 3 dB

down point set to the Cutoff Frequency

above. For most pulses the effects of this are

subtle. If this causes any part of the reference

to fall outside the tolerance bands, a warning

will be displayed. For some pulses, such as a

half-millisecond pulse with Simple pre- and

post-pulses, this filter will shape the pulse into

something that is more realistic for a shaker to

run.



Fig. 1: 200g, 0.5ms half-sine pulse with no filtering.

Fig. 2: 200g, 0.5ms half-sine pulse with 3,333 Hz filter.

The unfiltered 200g reference pulse (Fig. 1) contains frequency components that the shaker is unable to reproduce,

resulting in an unstable control loop. The filtered pulse (Fig. 2) removes these components. This necessarily

introduces a ripple into the reference’s pre- and post-pulse, but it enables this pulse to be run and controlled

accurately on the shaker.



Fig. 3: 100g, 6ms terminal sawtooth pulse with no filtering.

Fig. 4: 100g, 6ms terminal sawtooth pulse with 3,333 Hz filter.

NOTE: Pulses are scaled to the correct G level and then filtered. This is done so that filtering does not change the

damage profile of the pulse. Particularly for sawtooth pulses, filtering often creates a ripple at the top of the pulse.

This results in the Peak Ref (G) box in the Status Bar displaying a number that is not quite the same as what was

entered. For example, the Peak Ref for the depicted filtered terminal sawtooth pulse (Fig. 4) is 106.1g even though it

is a 100g pulse.



Shaker limits in shock mode

The Force field displays the peak G level of the shock multiplied by the Load. This is sometimes called “peak bump

force”. The warning box is blacked out because the Sine and Random force ratings are not directly applicable to shock

mode.

The Velocity field displays the peak velocity of the pulse. The warning box is blacked out because the Sine velocity

rating is not directly applicable to shock mode.

The Displacement field displays the peak displacement of the pulse. The warning box turns red when this number

exceeds the shaker’s displacement rating and the Run button is disabled. The warning box turns yellow at 80% of the

shaker’s displacement rating and a warning is displayed when the test is started.

WinVCS 2 Instruction Manual RealData Mode


Section 5: RealData Mode

The RealData mode of operation is separate from the other major modes and must be purchased as an additional

option. It is available on the toolbar alongside the other major modes of operation. RealData mode allows the user to

reproduce data collected from the field precisely as it was recorded.

In a typical application, accelerometers are placed at various points on a vehicle that is run on a test track. The data

from these accelerometers is recorded in real time. This data can then be used to reproduce the conditions from any

one of the accelerometers on a shaker in a lab.

RealData graphs

The RealData mode graphs display the pre-recorded test data and the real-time closed loop displays during the test.

The pre-recorded test data plots the response plot from the shaker. The real-time closed loop graphs show how the

system is operating.

Real Time Input and Output

• The Real Time Input graph displays the time

domain G level for each enabled input channel

accelerometer.

• The Real Time Output graph displays the time

domain voltage level of the output signal.

RealData Mode WinVCS 2 Instruction Manual


Response

The control and monitor response graphs display the pre-recorded response from the control and monitor

accelerometers.

• The Control Response graph displays the response

used by the software to adjust the demand output

to the shaker. The control response is a part of the

closed-loop control system.

• The Monitor Response graph displays the

response of other areas around the product or

shaker. This response is calculated separately and is

not a part of the closed-loop system.

Output Drive

The Output Drive graph displays the actual frequency-

domain drive signal output. The graph shows the

amplitude of the drive signal over the defined frequency

range. The software converts this signal to a time-

domain drive signal that is applied to the shaker

amplifier through the VCS I/O module.



Recording data

Data can be recorded directly by the software (usually via playback) into one of the accelerometer inputs from a DAQ

tape deck or other recording device. Data can also be collected directly by the software in the field on a separate

installation on a laptop.

There are a few important considerations in using the software to collect field data:

• A NI-DAQ Card-6036E (for PCMCIA) should be installed and used in the laptop. For additional information, refer

to your parts list.

• For field recording, Thermotron recommends a laptop computer with 1.6 GHz or better processor and 512 MB of

RAM running Windows XP or newer. NOTE: The quality of the video card will also affect performance.

• A data acquisition copy of the software should be installed on the laptop. To install a data acquisition copy of the

software, check the “Use this installation for acquisition only” check box on the product registration key dialog

box during installation. This allows the software to collect data, but prevents the installation from running any

tests.

Recording field data with WinVCS 2

NOTE: Before recording a RealData test, the accelerometer sensitivity should be verified using the Edit Accel

Sensitivity panel from the Calibration drop-down menu. See “Edit Accelerometer Sensitivity panel” in Section 6.

1. Select the RealData Mode button on the toolbar.

2. Press the Read Inputs button on the toolbar.

3. Enter the name of the file that

the recorded data will be saved

to. The extension *.rdf must be

used for all RealData files.

Unless specified otherwise, this

file will be saved in the main

WinVCS 2 directory.

4. Select the highest frequency

desired. This determines the

sample rate used to record the

data. Thus, selecting 2,500 Hz as

the highest desired frequency

will cause the data to be

sampled at 5,000 Hz.

Frequencies that can be

selected are 100, 250, 500,

1,000, 2,500, and 5,000 Hz, for

sample rates of 200, 500, 1,000, 2,000, 5,000, and 10,000 respectively. The higher the sample rate, the larger the

resulting data file will be.

5. Set the recording time limit. The recording runs for the specified time in hours, minutes, and seconds. If these

values are left at zero, the user must press Stop to end the recording.

6. Select which inputs to record on. Each recorded channel can be named in the space provided, which can be

useful when playing back the data on the shaker. If no name is given, the channel number is used to identify each

channel.

7. Press OK. The software starts recording the data as soon as the OK button is pressed. The data will then be

recorded for the time specified in step 5 or until Stop is pressed.



NOTE: You can watch the data being recorded in both the time domain (top) and frequency domain (bottom).

Data format

The data file has a header that identifies the file as a RealData file as well as describing the channel and sample rate

settings. The data is saved as a series of comma-separated G values. On each line of sample data the first channel is

listed first, followed by any other channels that were recorded. The next sample starts on the next line. The following

is an excerpt from the file recorded above:

Thermotron RealData File

Version 100

Sample Rate: 5000

Channels: 2

Engine Block,Dashboard

0.912,-1.527

0.262,-1.069

1.846,-0.006

0.928,0.461

1.599,0.570

0.618,0.684

2.998,1.946

1.029,2.109

2.716,2.557

1.176,2.294



RealData file sizes can vary greatly, depending upon the sample rate and the number of channels recorded. This

particular file ran for about two minutes and is about 8 MB. If only one channel had been recorded, the file would be

close to 4 MB. If only one channel had been recorded at a sample rate of 2,000 instead of 5,000, the file would be less

than 2 MB.

Once a RealData file is about 650 MB, the software will begin a new file with the same name but with “.001” added on

the end. Once the second file gets to 650 MB, another new file with “.002” is begun and so on. In this way, very long

tests are kept to a size that can be broken up and easily saved to CD. This also has the effect of limiting the test

length only by the size of the hard drive.

Configuring a RealData test

1. Select the RealData Mode button on the toolbar.





4. Select the Test Profile panel.

a. The RealData file field displays the

name of the file recorded in the

RealData format. Click on the Browse

button to browse the hard drive for the

RealDate file. NOTE: This is the only

way to locate RealData files.

b. In the Max Frequency field, enter the

maximum frequency the test will

reproduce. Any frequencies in the

RealData file that are higher than this

value are suppressed. Thus, the lower

500 Hz of a particular test can be

isolated, even if the original test was

sampled at 10,000 Hz.

The highest value this field should be

is half the sample rate of the original

RealData file. For example, a Sample

Rate of 5,000 equals a Max Frequency

of 2,500 Hz. This value can be set to

greater than half of the original sample

rate, but the reproduction effectively

works as if it is set to half of the

original sample rate.

c. From the Use Recorded Channel drop-down menu, select which channel from the RealData file to use to

control the test. If the channels were given names, these names will be displayed in this drop-down menu. If

the channels were not named, they will be identified by their channel number.

d. In the Max Acceleration field, enter the highest G level the test will exhibit. Anything that is a higher level

than this in the test profile will get clipped at this value.

i) To determine the maximum G level contained in a test, press the Find Max button. This could take a

long time, depending upon the size of the RealData file.

ii) A dialog box will open showing

where in the RealData file it is

currently scanning.

iii) If Stop Now is pressed, the software will stop scanning the file and the highest G level found to that

point will be put into the Max Acceleration field. NOTE: Allowing the test to be scanned will allow the

software to adjust its input for the maximum dynamic range possible. It can also be used to limit a test

where there are G levels exceeding the desired maximum.

e. Select the Control Channel and Monitor Channels to use by checking the appropriate check boxes. NOTE:

Only one control channel is allowed for this type of test. These channels are independent of the recorded

channel used when recording the test.

f. The File Info fields display various information about the recorded data file:

• Sample Rate is the sample rate that the RealData file was recorded at.

• Total Samples is the total number of samples found in the file, and Run Time is simply the Total

Samples divided by the Sample Rate, giving the total run time of the test. Because the file needs to be

scanned in order to find these values, and because scanning can take a long time, the user needs to

press the Scan button to get them. Scanning can be stopped by pressing the Stop Now button.

• The Graph does not get displayed until the file is scanned or one of the buttons below the test is

pressed. When a RealData file is first scanned, the first minute of the test will be displayed on the graph.

Press the <<Prev and/or Next>> buttons to move backwards and forwards through a test. Press

||<Start to return to the first minute of the test. To zoom in and out of the graph, press the + and –

Zoom buttons.

5. Select the Level Schedule panel. Up to eight levels can be defined, and each level can be individually enabled or

disabled. In the example below, levels 1, 2 and 3 are enabled and each has different options:

• Level 1 is set to run at 50% of the

level, will start at the beginning of the

file, and run for just 15 seconds. It will

not loop at all.

• Level 2 will run at the full 100%, again

starting at the beginning of the file,

and run for 1 minute. It will then loop

twice, which means that this level of

the test will run three times. This is a

subtle but important distinction. If

Loops is set to 0, the level runs once (it

doesn’t loop; that is it has 0 loops). If

Loops is set to 1, the level runs twice

(it loops back once), and so on.

• Level 3 also runs at 100% of level, but

starts 1 minute into the test and will

then run until the end of the file,

without looping.

By default, there is one level defined that

will run at 100%, start at the beginning of

the test, and run to the end without

looping.



Running a RealData test

When a RealData test runs, the system will first put out a series of quickly sweeping sine tones in order to determine

the response of the system. Once these are done, it will start the test and run it according to the defined Level

Schedule.

If there are any levels in the test that don’t start at the beginning of the file (for example, Level 3 in step 5 above), the

software has to seek out those starting points beforehand. This may take a while depending on how far into the test

the starting point is and how large the RealData file is.

While running, most of the screens are similar to screens in the other modes; however, the status panel on the left

side of the screen has new information:

• Control (G RMS) is the G RMS of the most recent piece of data taken

from the control channel.

• Drive (V RMS) is the current output voltage RMS.

• Target (G RMS) is the G RMS the system was aiming for during that piece

of data. Characteristics of the shaker, frequency limitations, and defined

max G levels may affect how close the Control and Target match up with

each other.

• Error is a rough estimation of how close the defined profile is to the

actual. If this value goes below -50% or above +200%, the test stops. This

value is averaged and does not represent the instantaneous values shown

in the Control and Target windows.

• Max Freq (Hz) is the maximum defined frequency for this test.

• Source Rate is the rate at which the source file was sampled.

• Level and Start Time show the current level of the test and the time at which the test started.

• The Elapsed field shows how much time has elapsed since the test started. If there are loops defined for the

current level, it displays that information in parentheses. In this case, the test has looped back 1 out of 2 times.

WinVCS 2 Instruction Manual Technical Displays and Interface Commands


Section 6: Technical Displays and Interface Commands

This section describes the System Options panel (including the networking options and amplifier control options)

and the Calibration panels.

System Options panel

1. To access the System Options panel, select the System Options icon from the toolbar or select

System Options from the Options drop-down menu. Select the General tab.

2. General Options:

• From the Units drop-down menu, select

the units of measurement to use. You

can select English or Metric.

• To automatically save the event log to

disk, check Log events to disk.

• To clear the event log when a test

begins, check Clear Log when begin

test.

• To load the last test used when the

software loads, check Load last test on

start.

• To play a sound when the software stops

on an abort condition, check Play sound

on abort.

3. Line Colors:

• Select line color and cursor options for

all graphs.

• To enable the graphical display of

warnings, check Enable warning

highlights.

4. TCP Server Options:

• To enable the software to act as a TCP/IP

server, check Enable TCP Server.

• In the TCP Server Port field, enter a valid TCP server port address.

5. Analog Output 2 Setup: An analog signal representing the currently running G level may be transmitted out of

analog output 2 on the vibration I/O module (VIO) by using the Analog Output 2 Setup fields. This signal may

be used by a chart recorder or for logging on a Thermotron chamber.

The voltage will be between 0 and 10 volts; define what G level is represented by 0 Volts (usually 0 G) and 10

Volts respectively. For example, if 0 V represents 0 G and 10 V represents 10 G, when a test is running at 5 G, a

5 V DC signal will be present on analog output 2.

6. I/O Options:

• In the GPIB Address field, enter the IEEE-488 address of the VCS computer. This field sets up the software

for communications over an installed GPIB interface.

• To enable the RS232 server, check Enable RS232 Server, then select the communications port and baud

rate.

Technical Displays and Interface Commands WinVCS 2 Instruction Manual


7. Web Server Options:

• To enable WebVCS (the built-in HTTP server), check Enable Web Server.

• In the Web Server Port field, enter the web server’s port location. The default port location is 80.

8. DAQ:

• In the NI-DAQ Device 1 field, enter the NI-DAQ device number. NOTE: The normal DAQ device number is 1.

• To enable a second NI-DAQ device, check NI-DAQ Device 2, then enter the second NI-DAQ device number.

• To enable the 100k input rate, check 100k Input Rate. NOTE: When running a NI-DAQ device with a PCIe

(PCI Express) slot, this box cannot be unchecked.

9. Amplifier Control:

NOTE: The Amplifier Control tab is available

only when a Thermotron machine controller

interface cable is used.

• To enable communications with the

amplifier, check Enable Amplifier

Communication. This displays the

amplifier controller toolbar.

• From the COM Port drop-down menu,

select the correct communications port

to use.

• To stop a test if the software loses

communication with the amplifier,

check Abort on Loss of

Communication.

• To enable the automatic start and stop

of the amplifier, check Auto Start and

Stop Amplifier.

• Digital I/O Amp Start: In order to use

this feature, one or more Digital I/O

Lines must be set to Start Amplifier.

This box then sets the Field and Gain

for these remote starts. NOTE: These

values will be overwritten when a test

starts. Consider using a digital I/O field

start to warm up a shaker under a

chamber after a long cold soak.

• Access Level Passwords: The amplifier control bar has four settings: Lock, Basic, Advanced, and Factory. In

Lock, users can view the Basic settings, but cannot change anything. Use Access Level Passwords to prevent

users from changing amplifier control parameters. To change a password, you must enter the old password,

enter the new password, and enter the new password again to confirm. The Factory access level is reserved

for setting up the system. If Factory access is necessary, call Thermotron Technical Support. The telephone

number is (616) 392-6550, and the fax number is (616) 393-4549.





Calibration menu commands

The Calibration drop-down menu allows you to enter accelerometer sensitivity ratings, verify the accuracy of the

system, and perform preventive maintenance checks on the VCS hardware and shaker.

Edit Accelerometer Sensitivity panel

The Edit Accelerometer Sensitivity panel allows you to enter and store the factory-certified sensitivity for each

accelerometer connected to an input channel. The software uses the values of the Edit Accelerometer Sensitivity

panel in all of its response calculations.

To access the Edit Accelerometer Sensitivity panel, select

Edit Accel Sensitivity from the Calibration drop-down

menu.

• If a channel is directly connected to an ICP

accelerometer, enter and save the factory-certified

sensitivity for the accelerometer.

• Once you are finished editing the fields, select OK to

load the new values and close the panel, or press the

Cancel button to close the panel without saving any

changes.



Live calibration

The live calibration function uses an internal single-frequency sine generator output to drive the shaker. The live

calibration function reads and displays the accelerometer response to the drive signal, one channel at a time. Use the

sine generator drive and accelerometer response data to perform the following functions:

• Verify operation of VCS software and hardware.

• Verify the sensitivity of any accelerometers with unknown sensitivity levels.

• Check the performance of the shaker and other shaker preventive maintenance checks.

NOTE: The live calibration function provides readings that are close to the accelerometer’s sensitivity. However, they

are not as accurate as a certified calibration reading from a calibration laboratory.

1. From the Calibration drop-down menu, select Live Calibration.

2. Enter values into any two of

the four Parameters fields.

The software automatically

calculates the other two

values. The Parameters fields

define the performance

factors for the sine wave and

shaker response.

• In the Frequency field,

enter the desired

frequency for the internal

sine generator. Enter any

value between 5 and

3,000 Hz within the limits

of your shaker.

• In the Displacement field, enter the desired peak-to-peak displacement of the armature. Enter any value

within the specified displacement limit of your shaker.

• In the Acceleration field, enter the desired acceleration factor of the shaker.

• In the Velocity field, enter the desired velocity of the armature. Make sure that this value is within the

specifications of your shaker.

NOTE: Pressing the Calibrate button without entering any information will use some good default values

(for example: 30 Hz @ 0.1 inch).

3. To begin the calibration process, press the Calibrate button. The software calculates the internal parameter

values and uses these values to calculate the sensitivity of each selected input channel.

4. To stop the current calibration process at any time, press the Stop button. If you stop a calibration, you will need

to start at step 1 to perform more calibration operations.

5. The Power Control fields set and adjust the power output of the drive signal.

a. In the Output % field, use the up and down arrow buttons to adjust the desired percentage of full output.

The corresponding peak voltage will be displayed in the Voltage field.

b. Select the radio button that provides the desired gain. For example, select the Tenths radio button to

increase or decrease the Output % field’s value by 0.1%.

6. From the Channels (mV / G) radio buttons, select the accelerometer input channel that you wish to test.

7. To place the displayed channel’s reading into temporary storage, press the Save Channel button. The software

displays the saved reading next to the channel’s radio button.



8. Perform steps 3 through 5 to check the sensitivity for all the desired accelerometer input channels.

9. To save the new values in the Edit Accelerometer Sensitivity panel, press OK. The software uses these values to

calculate the response from the shaker.

10. To exit from Live Calibration without saving new values in the Edit Accelerometer Sensitivity panel, press

Cancel.

Input Verification panel

The Input Verification panel allows you to verify the internal accuracy of the input channels. A sine oscillator capable

of developing a 50-to-150 mVrms signal between 5 and 4,500 Hz is needed to use the input verification function.

1. To access the Input Verification panel, select Input

Verification from the Calibration menu.

2. To have the NI-DAQ card perform an internal self-calibration,

press the Self Calibrate button.

3. Connect the sine oscillator to the Channel 1 input on the I/O

module’s rear panel.

4. Set the sine oscillator to between 50 and 150 mVrms, and

between 500 and 1,500 Hz.

5. In the Input Voltage field, enter the exact voltage reading from

the sine oscillator.

6. To start the test, press the Start Verification button.

7. Click on the Input Channel radio button for the channel you

are testing.

8. Sweep the sine oscillator from 5 Hz to 3,000 Hz. Make sure the

Error field stays within ±0.5 dB during the entire sweep.

9. Press the Stop Verification button to stop the test, and turn off the sine oscillator.

10. Move the sine oscillator connection to the next channel, and turn the channel’s ICP switch to OFF.

11. Repeat steps 3 through 9 for each channel.

12. Repeat steps 3 through 9 for each channel again, but set the oscillator’s voltage to 1.0 Vrms for each test.

13. Press the Stop Verification button to stop the test.

14. Press Close to close the Input Verification panel.

15. Turn off the sine oscillator and disconnect it from the I/O module.

The fields in the Amplitude section display the High and Low voltage values recorded, and the peak-to-peak (Pk-Pk)

during the last second or so. If the low voltage value is not equal to or very close to the negative of the high voltage

value, there is a DC offset in the system. NOTE: DC offsets usually don’t cause problems unless they are very large.



Using the TCP/IP or GPIB computer interface

The WinVCS 2 software can be operated from a remote computer using one of two protocols:

• The TCP/IP interface allows you to communicate over any TCP/IP network, including the Internet.

• The GPIB interface allows you to communicate over an IEEE-488 interface. NOTE: A personal computer equipped

with a National Instruments AT-GPIB/TNT card is required to use the IEEE-488 interface.

Setting up and using the TCP/IP interface

The TCP/IP interface allows you to operate the software over any standard TCP/IP network. In order to use the TCP/IP

interface, the VCS computer must be networked with a remote computer via a local network or the Internet. Once the

network is installed, both computers must be set up to use the TCP/IP interface. For additional information, refer to

your Windows and/or network card documentation.

Setting up the GPIB interface

Thermotron uses a National Instruments AT-GPIB/TNT card for the IEEE-488 interface. If you purchased the software

with the GPIB option, the interface is set up. If you purchase the card yourself, follow the manufacturer’s instructions

to install the card into the VCS computer. For additional information, refer to your Windows and/or network card

documentation.

Using the command set

Once you install the GPIB, TCP/IP, or both interfaces, you can operate the VCS computer using the command set

listed below. The main difference between the GPIB and TCP/IP is the acknowledgement protocol:

• TCP/IP sends an OK back for commands that do not have an associated return response.

• GPIB does not send anything back for commands that do not have an associated return response.

The commands are formatted as operational and query commands:

• An operational command performs a specific operation. It consists of an ASCII command without a question

mark.

• A query command requests information from the software. It consists of an ASCII command with a question

mark.

The data can be in character-string, fixed integer, scientific, or command-specific notation:

• Character-string format sends back alphanumeric characters, such as a program file name and path.

• Fixed integer format sends back a predefined number of integers. For example, a response denoted as nnnnn

will send back 00500 for a value of 500.

• Scientific notation uses a 14-character format as follows: ±x.nnnnnnne±eee where x is the whole number

portion, n is the decimal portion, and e is the exponent. The sign (±) is always present for the number and its

exponent. For example, +1.994561e+001 equals the number 19.94561.

• Command-specific notation is explained in each command’s description.

General purpose commands

filename? Returns the full pathname of the currently loaded file. Untitled is returned if a file is not loaded.

package? Returns the currently loaded mode.

gotorandom Switches to random mode (included for backward compatibility).

gotoshock Switches to shock mode (included for backward compatibility).

gotosine Switches to sine mode (included for backward compatibility).



gotovcs Does nothing (included for backward compatibility).

hold Holds the currently running test.

lastcode? Returns the current program state code:

aborted – General abort condition

controlabort – Test aborted due to control limits

emptytest – Test was not completely defined

endoftest – Test ended normally

holding – Test is holding

monitorabort – Test aborted due to monitor limits

openloopabort – Open loop detected

operatorstop – Operator stopped controller

outputabort – Drive output limits reached

remotestop – Test stopped remotely

running – Test running at level

starting – Test ramping up to level

stopped – General stopped condition

level? Returns the test’s current level number. Format: nn

load testname Loads testname into WinVCS 2. Testname must be a valid test file; the test file must include the

*.vcs file extension. If the test is not in the default directory, a path must be supplied.

For example: load C:\WinVCS 2\random\navmat3.vcs

resume Resumes a held test.

run Runs the currently loaded test.

statenumber? Returns the current program state number:

01 – Stopped

02 – Ramping up to level

03 – At level and running

stop Stops the currently loaded test.

storedata Stores the current data as a stored data file. The file name is the recorded data file name with a

sequential extension, starting with 001.

timeleft? Returns the time remaining in the current test. Format: hh:mm:ss

timeoday? or time? Returns the current time of day. Format: hh:mm:ss

Random mode commands

bandwidth? Returns the current maximum frequency in hertz. Format: nnnnn

controlrms? Returns the control channel’s G or m/s2 RMS level in scientific notation.

demandrms? Returns the G or m/s2 RMS value for the current level’s demand plot in scientific notation.

driverms? Returns the current output (V RMS) in scientific notation.

numlines? Returns the number of lines in the current test. Can be 100, 200, 400, 800, 1600, or 3200.



Sine mode commands

controldpk? Returns the control response displacement at the current frequency in scientific notation.

controlgpk? Returns the control response acceleration peak (G’s) at the current frequency in scientific

notation.

controltype? Returns the control type for the current frequency:

0 – Acceleration

1 – Velocity

2 – Displacement

controlvpk? Returns the control response velocity peak at the current frequency in scientific notation.

cyclecount? Returns how many cycles have been completed so far. Format: nnn

demandgpk? Returns the current reference acceleration peak (G’s), in scientific notation.

frequency? Returns the current frequency of a swept test in scientific notation.

outputvoltage? Returns the voltage being output at the current frequency in scientific notation.

Shock mode commands

controlgpk? Returns the current control response acceleration peak (G’s) in scientific notation.

demandms? Returns the width of the pulse in ms in scientific notation.

demandgpk? Returns the defined acceleration peak (G’s) for this level in scientific notation.

outputvoltage? Returns the current peak output in volts in scientific notation.

prepost? Returns the pre- and post-pulse percentage in scientific notation.

pulsecount? Returns the number of successfully run pulses for the current level. Format: nnnnn

Using the WinVCS 2 web server

WinVCS 2 features a built-in basic HTTP server that is capable of handling requests for HTML documents. The built-in

web server is not intended as a replacement for a general-purpose web server and has limited functionality:

• The size of files served is limited to 512 Kb.

• The only supported MIME types are HTML (text) and image (jpeg and gif). NOTE: Any file with an extension other

than *.gif, *.jpeg, or *.JPG is treated as an HTML file.

• No security features (username/password or IP banning) are present. If any control functionality is implemented

(start/stop, loading tests, etc.), Thermotron recommends that the software be limited to small local area networks.

• CGI scripting and server side image maps are not supported.

• Downloading Java applets is not supported.

• WebVCS has a limited capacity and cannot handle a large number of simultaneous connections. Scalability of the

system depends on the operating system and system resources.

• WebVCS implements a small subset of the HTTP 1.0 specification. Time stamps on files are ignored and GET is the

only request that can be made. The only error codes returned are 200 (success) and 404 (file not found).

By default all the web pages are located in the C:\Program Files\WinVCS 2\Web directory. The default start page is

Index.HTML. An example setup is also located in the C:\Program Files\WinVCS 2\Web directory. These files contain

examples of WebVCS tags that allow remote monitoring of random, sine, and shock tests.

HTML extensions

WinVCS 2 includes a special server side tag that allows web browsers to interact with the WinVCS 2 software to get

status information and to operate the vibration control system. This tag is in the following form:

<WINVCS>command</WINVCS>

where command is any of the supported computer interface commands listed above. This tag may appear anywhere

in the HTML code, and must be in uppercase letters, although the program will return the command in lowercase

letters. For example, to load the profile NavMat.vcs:

<WINVCS>load NavMat.vcs</WINVCS>

When the server processes the web page, it replaces the entire tag with the output returned from the system. For

example:

Control Response: <WINVCS>controlrms?</WINVCS> G RMS Monitor Response: <WINVCS>monitorrms?</WINVCS> G RMS Drive: <WINVCS>driverms?</WINVCS> V RMS 

returns the following HTML over the network (the white space in the code is intentional):

Control Response: +3.014059e+000 G RMS Monitor Response: +3.182043e+000 G RMS Drive: +3.052916e-002 V RMS

This is displayed as follows in the web browser:

Control Response: +3.014059e+000 G RMS

Monitor Response: +3.182043e+000 G RMS

Drive: +3.052916e-002 V RMS

The default web pages are located in C:\Program Files\WinVCS 2\Web\*. Each mode of operation has its own default

web page.

WinVCS 2 Instruction Manual VCS Electronic Interface


Section 7: VCS Electronic Interface

Installing the hardware

The following procedure describes how to install the VCS components and cabling. Refer to the instrumentation

drawing located in the shaker manual’s engineering drawings. You will need a flathead screwdriver and the provided

cables.

Unpacking the VCS

1. Carefully remove the components from the shipping containers. Avoid damaging the front panel and rear panel

connectors. Accessory kits may be packaged separately.

2. Check the items received against the packing slip. Save all shipping containers and packing material until the

system has been inspected and operationally checked.

3. Inspect all panels for dents, chipped or scratched paint, or other physical damage.

4. Check for bent or broken switches and connectors. Photos of damage are recommended to substantiate claims.

Installation procedure

1. Remove main power from the control console.

2. Install all of the electronic equipment according to the assembly drawing.

3. Connect the PC to the breakout box using cable p/n 1084340.

2. Connect the accelerometer power supply to the breakout box using cable p/n 1084235.

3. Connect the output signal filter to the breakout box using cable p/n 1196901.

4. Connect the output signal filter to J4 of the machine controller with a coaxial cable.

5. Put the 50-ohm terminator on J2 of the machine controller.

6. Connect at least one accelerometer to the accelerometer power supply.

7. Connect a printer, if supplied.

8. Close any open console doors.

9. Restore main power to the control console.

VCS Electronic Interface WinVCS 2 Instruction Manual


Calling Thermotron for technical support

1. Make sure you have the following information before you call:

• All the failure indications provided by the WinVCS 2 software.

• All the configuration information supplied by Thermotron.

• If you were troubleshooting the WinVCS 2 software, what steps did you perform and what were the results?

• What functions work on the WinVCS 2 software?

2. Contact your local Thermotron Field Service Office, or contact the Technical Liaison Assistants at Thermotron

Industries in Holland, Michigan. The telephone number is (616) 392-6550, and the fax number is (616) 393-4549.

Ordering a replacement part

Write or telephone the Thermotron Parts and Logistics Department. The telephone number is (616) 392-6550, and the

fax number is (616) 393-4549.

Include the following information in any correspondence:

• The complete seven-digit Thermotron part number. Refer to the parts list for the correct part number.

• The serial number of the shaker for which the replacement is being ordered.

• The specific problem with the failed part. Include a copy of all the configuration information supplied by

Thermotron.

• A purchase order number.

What to do if the VCS fails

1. Contact your local Thermotron Field Service office. A service representative will help you determine the nature of

the problem and the proper steps to resolving the problem.

2. To return a Thermotron part or instrument, follow these steps:

a. Contact the Parts and Logistics department at Thermotron Industries in Holland, Michigan, USA. The

telephone number is (616) 392-6550, and the fax number is (616) 393-4549.

b. When you telephone, our staff needs the following information: your name, the name of your company, the

model and serial number of your shaker, and a brief description of the failure.

c. Parts and Logistics will authorize the return of the material and issue a Returned Material Tag (RMT) number.

d. Write the name and telephone number of a contact person at your location and the RMT number on the

packing list.

e. Write the RMT number in a visible location on the outside of the shipping container.

f. Ship all parts FOB to:

Thermotron Industries

836 Brooks Avenue

Holland, MI 49423

ATTN: (Issued RMT Number)

NOTE: You may be asked for a purchase order number before a replacement part can be shipped. Full credit

will be issued under the terms and limits of the warranty if the defective part is received at Thermotron

within 30 days of issuance of the RMT number.

WinVCS 2 Instruction Manual Appendix A: Specific Mode Features and Capabilities

Thermotron Industries This generic manual is not intended to be used to operate your equipment. A-1

Appendix A: Specific Mode Features and Capabilities

Random mode

Data acquisition

Control A/D Up to 8 input channels

Monitor A/D Up to 16 input channels (more than 8 requires a second VIO box)

Resolution The 16-bit A/D converter provides 1/64k resolution

Sample frequency 30,000 Hz

Maximum frequency User programmable, up to 3,000 Hz

Analysis resolution 100, 200, 400, 800, 1,600, or 3,200 lines.

Maximum grms level System and load dependent

Monitor output

Monitor A/D Multiplexed output from the 8 (or 16) inputs

Voltage 20 V peak-to-peak maximum

Current 20 mA maximum current

Reference spectrum Up to 120 breakpoints per profile

Up to 120 breakpoints for tolerance and abort lines

rms over/under programmable independently

Level scheduling Up to 32 levels per profile

Time programmable at each level

Data storage Automatic graph storage during stop or abort operations

Manual graph storage from the graphic screens

Manual drive storage at user command (model)

Automatic drive storage

Test duration User-determined

System protection Open loop detection at the beginning of each test

Over/under rms detection during each test

Over/under lines past abort level detection during each test

Appendix A: Specific Mode Features and Capabilities WinVCS 2 Instruction Manual

A-2 This generic manual is not intended to be used to operate your equipment. Thermotron Industries

Sine mode

Data acquisition

Control A/D Up to 8 input channels

Monitor A/D Up to 16 input channels (more than 8 requires a second VIO box)

Resolution The 16-bit A/D converter provides 1/64k resolution

Sample frequency 100,000 Hz

Max frequency User programmable, up to 3,000 Hz

Display Demand and response are shown

Selectable acceleration, velocity, or displacement

Frequency

Frequency range 1 Hz – 3,000 Hz

Control characteristics

Acceleration 0.02 g to 100 gpk

Velocity 0.01 in/s to 100 in/s

Displacement .01 in. to 3 in. p-p (dependent upon system capabilities)

Control response 1 to 8 channels may be used in any combination for single point or average

control

Test definition

Demand Up to 120 breakpoints in terms of acceleration, velocity, and displacement per

test

Tolerance and abort Up to 120 segments for tolerance and abort limits

rms abort Independently programmable over and under grms

Stored tests Number of tests limited only by the size of the hard drive

Sweep characteristics

Direction Up, down, or bi-directional

Type Linear or logarithmic

Rate Logarithmic octave: 0 to 99 oct/min

Logarithmic decade: 0 to 99 dec/min

Linear: 0.01 to 5,000 Hz/min

Number of sweeps 0 to 9,999

Data storage Automatic graph storage at stop or abort

Manual graph storage from graphic screens

Test program storage during the define function

Number of data records Only limited by the size of the hard drive


Time duration or number of cycles are programmable at each level


Over/under peak voltage detection during each test

WinVCS 2 Instruction Manual Appendix A: Specific Mode Features and Capabilities

Thermotron Industries This generic manual is not intended to be used to operate your equipment. A-3

Shock mode

Data acquisition

Control A/D One channel at a time; up to 8 monitor channels

Resolution 16-bit A/D converter

Display Demand and response are shown

Selectable acceleration, velocity, or displacement

Reference profile

Pulse type Half sine

Terminal peak sawtooth

Initial peak sawtooth

Triangle

Rectangle/trapezoidal

Pulse duration As narrow as 1 ms

Pulse direction Selectable positive or negative

Test result storage Saved to user-defined file location

Limited only by the size of the hard drive

Test reference storage Number of profiles limited only by the size of the hard drive


Number of pulses programmable at each level

Data storage Automatic graph storage at stop or abort

Manual graph storage from graphic screens

Program is saved during define function

Test duration Programmable number of pulses


Over/under abort detection during each test

RealData mode

Data acquisition

Control A/D One channel at a time; up to 8 monitor channels

Resolution 16-bit A/D converter

Display Real-time input and output

Level scheduling 8 level schedules with up to 1,000 loops per level

Test duration Limited only by available space on the hard drive


Over/under abort detection during each test

Appendix A: Specific Mode Features and Capabilities WinVCS 2 Instruction Manual

A-4 This generic manual is not intended to be used to operate your equipment. Thermotron Industries

WinVCS 2 Instruction Manual Appendix B: Definition of Terms

Thermotron Industries This generic manual is not intended to be used to operate your equipment. B-1

Appendix B: Definition of Terms

A/D analog-to-digital

DSP digital signal processor

EVTS electrodynamic vibration testing system (shaker)

g gravity as a measure of acceleration

g2/Hz units of gravity squared divided by the signal bandwidth; the mathematical expression of power

spectral density

Hz hertz

in inches as a measure of displacement

in/s inches per second as a measure of velocity

ms milliseconds

mV/g millivolts per unit of gravity; used to measure accelerometer response signals

p-p or pk-pk peak-to-peak

pk peak

PSD power spectral density

rms root-mean-square

V volts

WebVCS WinVCS 2 web server

WinVCS 2 vibration control system software

Common terms

The following terms are used to describe functions of vibration testing. Some of the definitions listed below are

followed by examples that help apply them to their vibration testing usage.

acceleration The rate of change of velocity with respect to time, usually along a specified axis, often

measured in G’s (gravitational units).

As a shaker moves from peak to peak, it stops during the instant it changes direction. The

shaker armature must accelerate from stop to maximum velocity to maintain the frequency (or

power spectral density in random testing) and displacement induced by the drive signal and

field coils.

amplitude The magnitude of variation (in a changing quantity) from its zero value. Amplitude is modified

with an adjective such as peak, RMS, average, etc.

The amplitude of the drive current is increased to apply more force to the shaker. As the force

is increased, the acceleration amplitude at the armature increases.

breakpoint A programmed reference point for calculating amplitude during random or sine testing.

convolution A mathematical way of combining two signals to form a third signal.

displacement The change in position from lowest to highest points.

If the armature moves 0.4 inches up from center and 0.4 inches down from center, its

displacement is 0.8 inches peak-to-peak.

Appendix B: Definition of Terms WinVCS 2 Instruction Manual

B-2 This generic manual is not intended to be used to operate your equipment. Thermotron Industries

drive Specific voltage waveforms applied to the armature to control its movement.

force The energy applied to the shaker to move the armature, fixturing, and product. Force is found

by using the following formula:

Force = mass * acceleration

On a shaker, the mass of the shaker load is the total moving weight of the armature, fixturing,

and product.

frequency The number of occurrences per period of time, normally expressed in hertz (Hz).

In sine testing, the drive signal outputs one specific frequency. In random testing, the drive

signal outputs multiple frequencies within a specified bandwidth.

harmonic A sinusoidal quantity that is an integer multiple of some fundamental frequency (1X).

Example: 1X=100 Hz; 2X = 200 Hz; 3X = 300 Hz; etc.

isolation A reduction in the severity of transmitted motion, usually attained by proper use of a resilient

support. The shaker’s air isolation system uses air bags to isolate the shaker’s vibration from

the floor.

octave The interval between two frequencies, differing by a ratio of 2:1. The upper octaves of 100 Hz

are 200 Hz, 400 Hz, 800 Hz, etc.

PSD Power spectral density, the term used to describe the intensity of random vibration. PSD is

measured in mean-square acceleration per bandwidth of frequency spectrum (g2/Hz).

random vibration Vibration with a specified average PSD over some bandwidth but with no periodic or

deterministic components.

resonance The frequency at which a constant force input results in maximum response. During vibration

testing, the acceleration of the product jumps up dramatically at its resonant frequency.

sine vibration Vibration of one single frequency, typically measured in hertz.

shock vibration Application of a single acceleration waveform in the form of a pulse. A shock waveform is

typically measured in peak gravity level (g’s peak).

transducer A device, such as an accelerometer, that converts mechanical energy into an electrical signal.

transmissibility Ratio of response motion to input motion.

velocity The rate of change of displacement per unit of time, often in inches per second.

If a shaker can experience a 1” displacement at 12 Hz, the shaker’s maximum velocity is

[V= π(12)(1)], about 37 inches per second.



Special definitions

Accelerometers

An accelerometer is a device used to sense motion through the armature, and sometimes on the product. A typical

accelerometer for electrodynamic shaker applications consists of a cross-section of quartz (or quartz-like synthetic)

crystal, suspended in a special mount. The mount’s design takes advantage of a special property of the quartz crystal:

the piezoelectric effect. The piezoelectric effect is the ability of quartz crystals to output a small electrical voltage

when they are stressed, compressed, or strained.

Each accelerometer must be accurately gauged and certified to output so many microvolts, or picocoulombs per g of

acceleration (pc).

Two types of piezoelectric accelerometers are commonly used today: charge type and integrated electronics

piezoelectric (IEPE) accelerometers. The charge type accelerometers directly output the picocoulombs sensed by the

crystals. The IEPE type accelerometers have a built-in electronic amplifier. The amplifier boosts the signal into the

millivolts per units of gravity range. The amplified signal gives the reading a greater signal-to-noise ratio.

Sensor output voltages (including those from accelerometers) are usually interpreted differently in sine and random

testing. During sine testing, output is usually measured in millivolts peak. In random testing, outputs are measured in

millivolts rms. This becomes important when using test equipment to measure the outputs of the accelerometers.

Digital multimeters read in true rms, while oscilloscopes can read in peak voltage. When making sine measurements,

use the following formulas to convert between peak and rms.

rms * 1.414 = peak

peak * .707 = rms

Random testing

Random vibration is measured in power spectral density (PSD). PSD refers to the average energy contained within the

random test spectrum as a function of frequency. Although the output of a random test is by construction not

predictable at any given instant, a long-time average of the response should yield the specified PSD.

Random vibration testing is done to simulate the various real-world vibrations that a product will experience over the

course of its life. Random vibration testing is done to ensure that a product will continue to operate normally after

being exposed to the vibrations of transportation and normal use. This form of testing is also used to find

manufacturing defects in a product, such as unsoldered or poorly soldered components, before the product leaves

the manufacturing facility. There are three types of random vibration testing:

• “Standard” random: A broadband or narrow band vibration with no periodic or deterministic characteristics.

• Sine on random: A fixed or swept sine wave vibration combined with a broadband random vibration.

• Random on random: One or more narrow band random vibrations swept onto a broadband random vibration.

For the purposes of calculating force and adjusting instruments, all random measurements are in RMS.

Sine testing

Sine testing applies one frequency at a time to the shaker. Audibly, sine can be compared to a single note as played

on a piano. Sine is sometimes used for vibration testing, but more often for R&D, maintenance, and calibration. Sine

mode is preferred when testing for resonant frequencies and calibrating instruments.

At one time, sine wave testing was the most popular form of vibration testing, but because sine wave testing does not

reflect “real world vibrations” it has largely been replaced by random vibration testing. Sine wave testing is still used

to determine the resonance of a product and to find the amplification (Q) of a product at resonance. There are three

types of sine wave testing:

• Dwell: A product is vibrated at a specific frequency for a specific amount of time, such as 2 G’s at 20 Hz.

• Sweep: A product is vibrated at a range of frequencies for a specific amount of time.



• Resonance search and dwell: A sine sweep test is performed and, once resonance is found, the product is

vibrated at that frequency for a specific amount of time.

For the purposes of calculating force and adjusting instruments, all sine measurements are in scaled peak voltage.

Shock testing

Shock testing applies a single acceleration waveform to the shaker in the form of a shock pulse. At the shaker, the

shock pulse is characterized by sudden bursts and larger displacements that develop significant internal forces in the

product. Shock pulses are used to test components that may be subject to sudden impacts in their real-world

environments. A shock pulse is normally measured in its peak gravity level (g’s peak).

Shock testing is used to simulate the various abrupt vibrations (shocks) a product could experience over the course of

its life. There are several types of shock testing:

• Classic shock: This test reproduces a specific signal with a specific force for a specific amount of time, such as

half sine at 25 G’s for 11 milliseconds.

• SRS (shock response spectrum): This test reproduces a signal that covers a broad frequency range. The test is

defined by the peak response of ideal resonators subjected to the shock. For given shaker limits, more damage

can generally be achieved by SRS shocks than by classic shocks.

• Specific shock: Shock tests have been developed to simulate specific types of shock that a product may

experience, such as drop tests and vehicular crash tests.

For the purposes of calculating force and adjusting instruments, all shock measurements are in peak gravity level.

RealData testing

The RealData mode of operation is separate from the other major modes of sine, random, and shock, and must be

purchased as an additional option. It is available on the toolbar alongside the other major modes of operation.

RealData mode allows the user to reproduce data collected from the field precisely as it was recorded.

In a typical application, accelerometers can be placed at various points on a vehicle that is run on a test track. The

data from these accelerometers is recorded in real time. This data can then be used to reproduce the conditions from

any one of the accelerometers on a shaker in a lab.



Formulas

There are a few basic formulas that one needs to know and understand to successfully use an electrodynamic shaker

for vibration testing. The following section includes the most frequently used formulas and examples of how to use

those formulas to design a successful vibration test. The coefficients used below assume units of pounds (force), g’s

(acceleration), inches/second (velocity), inches (displacement), and hertz (frequency).

General formulas

Force = mass * acceleration F = m * a

Common sine formulas

Displacement = Acceleration / (0.0511 * Frequency2) D = A / (0.0511 * F

2)

Velocity = 61.44 * (Acceleration / Frequency) V = 61.44 * (A / F)

Common random formulas

PSD or G2 / Hz = Acceleration

2 / ∆Frequency Bandwidth PSD or G

2 / Hz = A

2 / ∆F

G’s RMS = √∆Frequency Bandwidth * PSD

Random Displacement = 42.8 * √(PSD / Frequency3)

NOTE: The formula for random displacement is primarily used for random tests below 20 Hz.

Examples

• Given a fixture weight of 100 pounds, a product weight of 55 pounds, a test level of 10 G’s, and a standard 24-

inch diameter magnesium armature (85 pounds), the system force is 2,400 foot-pounds. The appropriate formula

to use is Force = mass * acceleration. Thus:

Force = (100 + 55 + 85) * 10

F = 2,400

• Given a frequency of 10 Hz and an acceleration of 5 G’s peak, the displacement is approximately one-inch peak

to peak and the velocity is approximately 31.0 inches/second. The appropriate formulas to use are: displacement

= acceleration / (0.0511 * frequency2) and velocity = 61.44 * (acceleration / frequency). Thus:

D = 5 / (0.0511 * 102)

D = 5 / 5.11

D = 0.98

and

V = 61.44 * (5 /10)

V = 61.44 * 0.5

V = 30.72

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