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National Instruments Switches

ni.com | NI CONFIDENTIAL

Raviteja Chivukula

Why the Need for Switches?Why the Need for Switches?Why the Need for Switches?Why the Need for Switches?

• Nearly every system can benefit from switching

• Increases channel count

• Adds measurement flexibility

• Simplifies test fixture

• Decreases cost

3ni.com | NI CONFIDENTIAL

Test Instruments Test Points Solution

Stimulus/Resp 1 Digitizer, 1 Arb 20 DUTs SWITCHING

Temperature 1 DMM 200 RTDs SWITCHING

Test ArchitectureTest ArchitectureTest ArchitectureTest Architecture

DMMDMMDMMDMM

ArbArbArbArb////FunctGenFunctGenFunctGenFunctGen

DigitizerDigitizerDigitizerDigitizer

Devices Under TestDevices Under TestDevices Under TestDevices Under TestSwitch HardwareSwitch HardwareSwitch HardwareSwitch Hardware

MatrixMatrixMatrixMatrix


RFRFRFRF AnalyzerAnalyzerAnalyzerAnalyzer

PowerPowerPowerPower SupplySupplySupplySupply

RFRFRFRF GeneratorGeneratorGeneratorGenerator

MatrixMatrixMatrixMatrix

Gen. PurposeGen. PurposeGen. PurposeGen. Purpose

MuxMuxMuxMux

Webcast OverviewWebcast OverviewWebcast OverviewWebcast Overview

A. Switch Matrix Basics

B. NI Products offered

C. Programming NI Switch Cards


Switch Matrix BasicsSwitch Matrix BasicsSwitch Matrix BasicsSwitch Matrix Basics• Switch Topologies


• Switch Topologies

• Switching Modes

• Relay Types

• Relay Life & Protection

• Specifications

Switch Topologies


Switch Topologies

Common Switch Common Switch Common Switch Common Switch TopologiesTopologiesTopologiesTopologies


General Purpose Matrix

MultiplexerNI 5122

Scope

NI 5421

Arb

Topologies: General PurposeTopologies: General PurposeTopologies: General PurposeTopologies: General Purpose

Single Single --Pole Pole

Single Single --Throw Throw

(SPST)(SPST)

Form A

Form B


• Individually controlled electromechanical relays

• Used in automated control

Single Single --Pole Pole

Double Double --Throw Throw

(SPDT)(SPDT)Form C

Topologies: MultiplexerTopologies: MultiplexerTopologies: MultiplexerTopologies: Multiplexer


• Multiple inputs to a single output

OR

• A single input to multiple outputs

Topologies: MatrixTopologies: MatrixTopologies: MatrixTopologies: Matrix

R0

R1

R2

C0 C1 C2 C3 C4 C5 C6 C7

4 x 8 Matrix


R3

• Any row can connect to any column

OR

• Any column can connect to any row

Matrix ConfigurationsMatrix ConfigurationsMatrix ConfigurationsMatrix Configurations

Source

Digitizer

DMM

DUT DUT DUT DUT

RowRow--ColumnColumn


SourceDMM DUT DUT

R0

R1

R2

Digitizer DUT DUT DUT

Digitizer

ColumnColumn--ColumnColumn

Topologies: Fault Insertion Topology (FIU)Topologies: Fault Insertion Topology (FIU)Topologies: Fault Insertion Topology (FIU)Topologies: Fault Insertion Topology (FIU)

• Allows faults to be inserted between

measurement devices and a DUT

• Used in HIL Applications

• Combines SPST with MUX topologies


• Combines SPST with MUX topologies

Topologies: External Relay Driver (PXITopologies: External Relay Driver (PXITopologies: External Relay Driver (PXITopologies: External Relay Driver (PXI----2567)2567)2567)2567)

Motor

High voltage/current motor


High Power

Relay

+

-

NI

Relay Driver

NI Switch Module

Independent TopologyIndependent TopologyIndependent TopologyIndependent Topology

• Allows you to utilize any connection that is physically possible with the module

• Allows for custom topologies


topologies

• Can control every individual relay on the board using the Relay Control functions and Connect Channels functions

PXI-2593’s Independent

Topology

RF Topologies: Sparse MatrixRF Topologies: Sparse MatrixRF Topologies: Sparse MatrixRF Topologies: Sparse Matrix

C0 C1C2 C3• Uses two multiplexers

• Any row can connect to any column

• Only one path allowed at a


R0

R1

R2

R3

4 x 4 Sparse Matrix

• Only one path allowed at a time

• Typically used in RF applications to eliminate stubs

RF Topologies: Blocking MatrixRF Topologies: Blocking MatrixRF Topologies: Blocking MatrixRF Topologies: Blocking Matrix


• Used in RF applications to minimize stubs

• Requires N MUXs of size (N-1)x1

• Any external terminal can connect to up to one other terminal, e.g. A->B, A->C, but not both simultaneously

RF Topologies: RF MatrixRF Topologies: RF MatrixRF Topologies: RF MatrixRF Topologies: RF Matrix

• Unconnected pins can cause RF switches to lose bandwidth.

• RF matrices (2540, 2541) have isolation relays to allow users to limit the number of unconnected


number of unconnected pins on a signal path.

• Making connections are identical to normal matrices and additional isolation relays are unseen to the customer

RF Topologies: RF Combiner / SwitchRF Topologies: RF Combiner / SwitchRF Topologies: RF Combiner / SwitchRF Topologies: RF Combiner / Switch

• Some customers may want

to “combine” or add signals

together.

• Using the 2790 RF combiner

allows users to do this.


allows users to do this.

• This is done by switching the

COM A Signal with the COM

B Signal through SUM AB

Switching Modes


Switching Modes

1111----Wire Switching ModeWire Switching ModeWire Switching ModeWire Switching Mode


e.g. This is a 1-wire 64x1 MUX similar to RSE

measurements for a multifunction DAQ



e.g. This is a 2-wire 32x1 MUX similar to

Differential measurements for a

multifunction DAQ



e.g. This is a 4-wire 16x1 MUX

Multiple Bank MultiplexersMultiple Bank MultiplexersMultiple Bank MultiplexersMultiple Bank Multiplexers


e.g. This is a Dual 2-wire 12x1 MUX. Both are

on the same switch module.

Multiple Bank MatricesMultiple Bank MatricesMultiple Bank MatricesMultiple Bank Matrices


e.g. This is a Dual 4x64 Matrix. Both are on the

same switch module.

Relay Types


Relay Types

Electromechanical Armature Electromechanical Armature Electromechanical Armature Electromechanical Armature


Armature: NonArmature: NonArmature: NonArmature: Non----latching (SPST)latching (SPST)latching (SPST)latching (SPST)

•Relay closes when coil energizes

•Relay opens when power turned off


Note: NO=Normally Open

Armature: NonArmature: NonArmature: NonArmature: Non----latching (SPDT)latching (SPDT)latching (SPDT)latching (SPDT)

•Relay closes when coil energizes, connecting normally open to Com

•Relay opens when power turned off, connecting normally closed to Com


Latching (Behind the Scenes)Latching (Behind the Scenes)Latching (Behind the Scenes)Latching (Behind the Scenes)

• Relay remains in last set position until next operation


Armature: Latching RelaysArmature: Latching RelaysArmature: Latching RelaysArmature: Latching Relays

• Reduces noise for low level signal measurements

• Allows more simultaneous relays to be driven (PXI

has limited power)

• Use the Power Down Latching Relays After

Debounce property to de-energize relay


Debounce property to de-energize relay

• Latching is an attribute of the switch module/relay not

the programming (check specifications)

Electromechanical Reed RelayElectromechanical Reed RelayElectromechanical Reed RelayElectromechanical Reed Relay

• Two reeds physically contact when the coil is energized

• When coil is de-energized, reed spring force separates reeds

• Smaller than armature relays

Coil

Reed

Contact Inert Gas


• Smaller than armature relays (allows higher channel count)

• Faster than armature relays

• Not as robust as armature relays, particularly with overcurrent

Solid State RelaySolid State RelaySolid State RelaySolid State Relay

• Photo-sensitive MOSFET

responds to light from

LED

• Isolation barrier allows

relay to switch high

voltages


voltages

• LED restricts switching

speed

• Faster than

electromechanical relays

• Infinite life when used

within specifications

FET SwitchFET SwitchFET SwitchFET Switch

• CMOS transistors

• No additional isolation between

the control circuitry and the

signal path

Transparent to user


• Low voltage (±10V)

• Very fast switching rate

• Unlimited lifetime

• Very easily damaged

Relay Life & Protection


Relay Life & Protection

RelayRelayRelayRelay Life BasicsLife BasicsLife BasicsLife Basics

• Electromechanical relays have a known lifetime that is

listed in the Specifications.

• This lifetime is a “Bell Curve” Estimate of expected relay life


• This lifetime is a “Bell Curve” Estimate of expected relay life

• All Electromechanical relays will fail at some point.

• There are methods to delay the inevitable.

• FET and SSR relays will last a very long time if used

within specifications.

• Out of specification use will easily damage FET and SSR relays.

o Abuse of FET relays can cause damage to module.

Predictive MaintenancePredictive MaintenancePredictive MaintenancePredictive Maintenance

• Disclaimer: predicting relay life is never as easy as people claim

• Inductive vs. capacitive vs. purely resistive loads

Statistical variations on relays


• Statistical variations on relays

• Tools available to assist in predictive maintenance

• Relay count tracking on NI switch modules

• Relay replacement instructions

• Spare relay kits

Minimum Switching Current/Voltage with Minimum Switching Current/Voltage with Minimum Switching Current/Voltage with Minimum Switching Current/Voltage with

Electromechanical RelaysElectromechanical RelaysElectromechanical RelaysElectromechanical Relays

• Contaminants slowly build up on the

relay contacts

• A minimum load is required to spark and

burn off particulate in order to form a

solid connection


solid connection

• Note: Reed, SSR, and FET relays are not

affected

ALL Electromechanical

Armature Relays have

issues with low signal

levels.

Switching Capacitive LoadsSwitching Capacitive LoadsSwitching Capacitive LoadsSwitching Capacitive Loads

• Need to protect relays from high inrush currents

caused by capacitor charge/discharge

• DMM / Power Supplies / SMU / Cables / EVERYTHINGEVERYTHINGEVERYTHINGEVERYTHING has

capacitive values that can cause damage.

• High inrush can cause relays contacts to weld


• High current from a Voltage Source (Power Supply /

Capacitor) charging another Capacitor (cables, etc)

• Add a resistor in series with the relay to limit

maximum current.

Switching Inductive loadsSwitching Inductive loadsSwitching Inductive loadsSwitching Inductive loads

• Inductors resist a change in current and create a very

high voltage when they are disconnected.

• This high voltage can damage relays and other

components.

• Use Zener Diodes/Metal Oxide Varistors to provide a

dissipation path for this excess voltage.


dissipation path for this excess voltage.

• Known as Inductor Flyback Protection

Relay Types and CapabilitiesRelay Types and CapabilitiesRelay Types and CapabilitiesRelay Types and Capabilities

Capabilities Armature Reed FET SSR

High-Power

High-SpeedBetter +

GoodBest

Better

BetterBetter

BestGood


High-Speed

Density/Module

Relay Life

Better +

Best Best

BestBest

Better

Better

Better

BestGood

Good

Good

Specifications


Specifications

Specifications of a typical matrix card

• Switch TypeSwitch TypeSwitch TypeSwitch Type Matrix

• Max Switching Voltage DCMax Switching Voltage DCMax Switching Voltage DCMax Switching Voltage DC 12 VDC

• Maximum Switching Voltage ACMaximum Switching Voltage ACMaximum Switching Voltage ACMaximum Switching Voltage AC 8 VAC

• Max Switching CurrentMax Switching CurrentMax Switching CurrentMax Switching Current 100 mA

• Maximum Carry CurrentMaximum Carry CurrentMaximum Carry CurrentMaximum Carry Current 100 mA

• Maximum Switching PowerMaximum Switching PowerMaximum Switching PowerMaximum Switching Power 1.2 W

BandwidthBandwidthBandwidthBandwidth 1 MHz


• BandwidthBandwidthBandwidthBandwidth 1 MHz

• Relay TypeRelay TypeRelay TypeRelay Type FET

• Path Resistance (Typical)Path Resistance (Typical)Path Resistance (Typical)Path Resistance (Typical) 9 Ohm

• Thermal EMFThermal EMFThermal EMFThermal EMF 10 µV

• Scan RateScan RateScan RateScan Rate 50000 cycles/s

• Matrix Config Wire ModeMatrix Config Wire ModeMatrix Config Wire ModeMatrix Config Wire Mode 1-wire

• Matrix Config BanksMatrix Config BanksMatrix Config BanksMatrix Config Banks 1

NI Switch ProductsNI Switch ProductsNI Switch ProductsNI Switch Products


NI Switch ProductsNI Switch ProductsNI Switch ProductsNI Switch Products

NI Switch Hardware Product Offering

0.51.3

2.5 2.74

5

26.5600

300

150

100

6030

10

Voltage - Up to 600 V Bandwidth - Up to 26.5 GHz


0.510

1

2

5

7

8

12

0.5

544

256

196

128

32 2410

Channels - Up to 544 Xpt Current - Up to 12 A

PXI-2566C. Form Factors

•NI offers switches in both PXI and SCXI form

•factors

•Benefits of PXI platform

• This is the future of NI switches

• Not an NI proprietary platform


SCXI-1166

• Largest selection of modules

•Benefits of SCXI platform

• Good for some applications with high channel density

• Allows users to control switches via USB or PCI

General Purpose


2569256925692569 2520252025202520 2522252225222522 2564256425642564 2586258625862586

Channel Count 100 80 53 16 10

Relay Form SPST SPST SPDT SPST SPST

RelayType EMR EMR EMR EMR EMR

Voltage 100 V 150 V 100 V 150 V 300 V

Current 1 A 2 A 2 A 5 A 12 A

Multiplexer


2530B2530B2530B2530B 2527252725272527 2575257525752575 2576257625762576 2584258425842584

# COM Wires 1-wire

2-wire

4-wire

1-wire

2-wire

4-wire

1-wire

2-wire

2-wire 1-wire

2-wire

Max Topology 128x1 64x1 198x1 64x1 12x1

RelayType Reed EMR EMR EMR Reed

Voltage 60 V 300 V 100 V 100 V 600 V

Current 0.4 A 2 A 1 A 1 A 0.5 A

Matrix


2532B2532B2532B2532B 2535/62535/62535/62535/6 2533/42533/42533/42533/4 2529252925292529

Topology 4x128

8x64

16x32

4x64 (2w)

8x32 (2w)

16x16 (2w)

4x136

8x68

4x64

8x32

4x32 (2w)

8x16 (2w)

RelayType Reed FET SSR EMR

Voltage 100 V 12 V 60 V 150 V

Current 0.5 A 0.1 A 1 A 2 A

SwitchBlockExpandable Large Matrix with Integrated Analog Bus

ModelModelModelModel Matrix SizeMatrix SizeMatrix SizeMatrix Size Max SwitchingMax SwitchingMax SwitchingMax Switching SpecsSpecsSpecsSpecs Max size Max size Max size Max size per carrierper carrierper carrierper carrier Max size Max size Max size Max size per chassisper chassisper chassisper chassis

NI 2810 4x43 150 V 1 A 20 W 4x258 4x1032


NI 2811 8x21 150 V 1 A 20 W 8x126 8x504

NI 2812 16x9 150 V 1 A 20 W 16x54 16x216

NI 2813 4x21 (2w) 150 V 1 A 20 W 4x126 4x504

NI 2814 8x9 (2w) 150 V 1 A 20 W 8x54 8x216

NI 2815 4x86 100 V 0.3 A 3 W 4x516 4x2064

NI 2816 8x46 100 V 0.3 A 3 W 8x276 8x1104

NI 2817 16x22 100 V 0.3 A 3 W 16x132 16x528

NI 2833 4x71 (2w) 100 V 2 A 60 W 4x213 (2w) 4x852 (2w)

NI 2834 8x34 (2w) 100 V 2 A 60 W 8x102 (2w) 8x108 (2w)

Fault Insertion Unit Ch0 DUT0

Channel 0

Channel 1Ch1 DUT1

Fault Bus A

Fault Bus B


ProductProductProductProduct PXIPXIPXIPXI----2510 2510 2510 2510 PXI(e)PXI(e)PXI(e)PXI(e)----2512251225122512 PXI(e)PXI(e)PXI(e)PXI(e)----2514251425142514

Max Current 2A 10A 40A

# of Channels 68 7 7

Relay Type EMR FET FET

# of Fault Bus Lines 2 (4 faults each) 2 2

Max Voltage 150 V 50 V 28 V

Module Width 1-slot 2-slot 2-slot

Programmable Resistor


2720272027202720 2725272527252725 2722272227222722 2727272727272727

Channels 10 18 5 9

Range 0-255 Ω 0-255 Ω 0-16 kΩ 0-16 kΩ

Resolution (bits) 8 8 16 16

Resolution (Ohms) 1 1 0.25 0.25

Voltage 60 V 60 V 60 V 60 V

RF


2541254125412541 2593259325932593 2547/482547/482547/482547/48 2543254325432543

Topology Matrix Multiplexer/ Matrix Multiplexer/SPDT Multiplexer

Channels 8x12 16x1 8x1/SPDT Dual 4x1

Frequency 300 MHz 500 MHz 2.7 GHz 6.6 GHz

RelayType Reed EMR EMR FET

Terminated No Yes/No No Yes

Microwave


2596/27962596/27962596/27962596/2796 2597/27972597/27972597/27972597/2797 2598/27982598/27982598/27982598/2798 2599/27992599/27992599/27992599/2799

Topology Dual SP6T SP6T Dual Transfer Dual SPDT

Bandwidth (GHz) 26.5/40 26.5/40 26.5/40 26.5/40

Terminated No Yes No No

Relay Type EMR EMR EMR EMR

Relay Radiall Radiall Radiall Radiall

Programming NI SwitchesProgramming NI SwitchesProgramming NI SwitchesProgramming NI Switches


Programming NI SwitchesProgramming NI SwitchesProgramming NI SwitchesProgramming NI Switches

NINININI----SWITCH Soft Front PanelSWITCH Soft Front PanelSWITCH Soft Front PanelSWITCH Soft Front Panel

• Equivalent to a test panel for DAQ devices

• Monitor relay positions with adjustable refresh rate

• Easily make your first connection

• Debugging tools

• Clickable switch schematics


• Clickable switch schematics

• Individual relay control for advanced users

• Access number of cycles on each relay

Exercise Approximate time to complete: 5 minutes

SwitchSwitchSwitchSwitch Soft Soft Soft Soft FronFronFronFront Panelt Panelt Panelt Panel


OBJECTIVE

To demonstrate the use of the Switch Soft Front Panel to

control switches.



Matrix

MUX

General Purpose AND MORE!

Programming NI Switches in LabVIEW Programming NI Switches in LabVIEW Programming NI Switches in LabVIEW Programming NI Switches in LabVIEW

Good Good Good Good ---- NINININI----SWITCHSWITCHSWITCHSWITCH

• IVI-compliant driver

• Session based; unique session for each module

• Supported in Real-Time

BEST BEST BEST BEST ---- NI Switch ExecutiveNI Switch ExecutiveNI Switch ExecutiveNI Switch Executive

• Graphical Configuration

• Multiple Modules

• Easiest programming

Better Better Better Better ---- NINININI----DAQmxDAQmxDAQmxDAQmx


BadBadBadBad ---- IVIIVIIVIIVI

• IVI-compliant driver

• Session based; unique session for each module

Better Better Better Better ---- NINININI----DAQmxDAQmxDAQmxDAQmx

• Not IVI-compliant

• Single scan list can span multiple devices

• Linux support for several modules

• Supported in Real-Time

• Fastest method

NI Switch APIsNI Switch APIsNI Switch APIsNI Switch APIs

NI-DAQmx

NI-SWITCH

NI Switch Executive


NI-DAQmx

NINININI----SWITCH VI TreeSWITCH VI TreeSWITCH VI TreeSWITCH VI Tree


Programming NI Switches in LabVIEW Programming NI Switches in LabVIEW Programming NI Switches in LabVIEW Programming NI Switches in LabVIEW

Initialize

Scanning

Immediate

Close


• Immediate Mode:Immediate Mode:Immediate Mode:Immediate Mode: Software sends commands during runtime

o Connect/Disconnect Channels

o Individual relay control (open and close)

• ScanningScanningScanningScanning: Multiple commands downloaded to module memory

o Each trigger advances module to next state in scan list

o Integrated hardware triggers decrease overall test time

o Software-defined triggers supported

Immediate ModeImmediate ModeImmediate ModeImmediate ModeConnect/ Disconnect Channels

NI-SWITCH


Immediate ModeImmediate ModeImmediate ModeImmediate ModeConnect/Disconnect Channels

NI-DAQmx


Immediate ModeImmediate ModeImmediate ModeImmediate ModeNI-Switch Relay Control API

NI-SWITCH


• Control specific relays by name

• For example: close kr2c3

• Ignores safety/exclusions/etc

Immediate ModeImmediate ModeImmediate ModeImmediate ModeDAQmx Relay Control API

NI-DAQmx


Exercise Approximate time to complete: 5 minutes

Immediate Mode ExamplesImmediate Mode ExamplesImmediate Mode ExamplesImmediate Mode Examples


OBJECTIVE

Open the Immediate mode examples from example finder.

Notice the differences between NI-SWITCH and NI-DAQmx

ScanningScanningScanningScanning

• Connections synchronized with an external HW trigger or with a software event

• Connection operations entered in a scan list that is then downloaded to the memory of switch

• Next connection retrieved from Switch memory at next trigger


trigger

• Scan list is not reconfigurable while running- have to stop task and redeploy new list to memory

• The first entry in the scan list is executed when the scan is initiated, trigger settings determine how the switch advances through subsequent entries in the list

Scan List Syntax: Scan Modes

ModeModeModeMode DescriptionDescriptionDescriptionDescription

Break Before Break Before Break Before Break Before

Make (default)Make (default)Make (default)Make (default)

Connections from previous scan list entry are

automatically disconnected before executing

the current scan list entry.

Disconnect actions (~) are not valid in this


Make (default)Make (default)Make (default)Make (default)Disconnect actions (~) are not valid in this

mode

No ActionNo ActionNo ActionNo Action

Connections remain connected until they are

explicitly disconnected by a disconnect action

(~)

Break After Break After Break After Break After

MakeMakeMakeMakeCurrently not supported.

Scan List Syntax Scan List Syntax Scan List Syntax Scan List Syntax

Character(s) Definition

-> Used in a connect action, “ch0->com0”

~ Used in a disconnect action, Valid only in No Action mode, “~ch0->com0”

; Wait for debounce after connection, “ch0->com0;”

* Listed in NI Switches Help


;

& Separates two actions, “ch0->com0 & ch9->com1”

&& Wait for debounce between connections, “ch0->com0 && ch9->com1”

:

Used when scanning through a range of channels, represents multiple

scan list entries, “ch0:7->com0;”

**A semicolon must appear after the connect action using a channel

range.

Scan List Syntax: NIScan List Syntax: NIScan List Syntax: NIScan List Syntax: NI----SWITCH SWITCH SWITCH SWITCH vsvsvsvs DAQmxDAQmxDAQmxDAQmx

• NI-Switch only allows one switch module to be

programmed at a time; therefore, a device indicator is

unnecessary

• ch0->com0; ch1->com0;

• DAQmx Switch allows multiple modules to be

programmed, and a device indicator must be included


programmed, and a device indicator must be included

• /Dev1/ch0->com0; /Dev2/ch1->com0;

Scanning Trigger SchemesScanning Trigger SchemesScanning Trigger SchemesScanning Trigger Schemes

• 3 trigger schemes for scanning:

• Software Scanning

• Synchronous Scanning

• HandshakingSynchronous scanning & handshaking are used with


• Synchronous scanning & handshaking are used with

DMMs and will be covered in greater depth in DMM

training

Software Scanning with NISoftware Scanning with NISoftware Scanning with NISoftware Scanning with NI----SWITCHSWITCHSWITCHSWITCH


Software Scanning with NISoftware Scanning with NISoftware Scanning with NISoftware Scanning with NI----DAQmxDAQmxDAQmxDAQmx


Example of Hardware ScanningExample of Hardware ScanningExample of Hardware ScanningExample of Hardware Scanning

• Hardware Scanning Trigger Schemes

• Synchronous Scanning

• Handshaking

• These modes of scanning use External Hardware

Triggers, rather than a software button, to advance


Triggers, rather than a software button, to advance

through the scan list. The next exercise will use the

DAQ Accessory’s Digital trigger to scan through a scan

list

MultiMultiMultiMulti----Module ScanningModule ScanningModule ScanningModule Scanning

• Recommend that customers use DAQmx for handshaking

• Must make external connections to pass analog signals

• PXI has no analog bus, so must be external

• SwitchBlock has analog bus, but only within SwitchBlock

• SCXI has analog bus


DMM/Switch Express VI: Switching TabDMM/Switch Express VI: Switching TabDMM/Switch Express VI: Switching TabDMM/Switch Express VI: Switching Tab

• Switching tab configures which switch and channels to use in scanning mode with the DMM

NoteNoteNoteNote: simulated


• NoteNoteNoteNote: simulated switch modules do not work with DMM/Switch Express VI

• (tab grayed out)

NI Switches HelpNI Switches HelpNI Switches HelpNI Switches Help

• Fundamentals (relay types, topologies, switching considerations, RF, Scanning)

• Devices (topologies, programming mode, triggering, expansion, etc.)


expansion, etc.)

• Programming (flow, mode, DMM scanning)

• Pinouts

• FirstFirstFirstFirst place you should look for non-specification-related questions

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