training plc

8/10/2019 Training PLC

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Presentation

On PLCSofcon Systems India Pvt. Ltd.C-87, Sector 88, NOIDA.

Uttar Pradesh.

E-mail: [email protected]


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INTRODUCTION TO

PROGRAMMABLE LOGICCONTROLLERS


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INDUSTRIAL CONTROL

SYSTEM (ICSs)

Encompasses several types of control

systems used in industrial production, includingSCADA, DCS, and PLCs.

ICSs are typically used in industries such as

electrical, water, oil, gas and data.


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INDUSTRIAL CONTROL

SYSTEM (ICSs)Industrial Control enables:

Mass production of continuous processes

such as oil refining, paper manufacturing,chemicals, power plants and many otherindustries.

Automation, with which a small staff of

operating personnel can operate a complexprocess from a central control room.


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TYPES OF INDUSTRIAL

CONTROL SYSTEMS

Process control systems can be characterized as

one or more of the following forms: Discrete

Continuous

Batch


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DISCRETE PROCESS

Found in manymanufacturing, motionand packagingapplications. Robotic

assembly, such as thatfound in automotiveproduction.

Most discrete

manufacturing involvesthe production ofdiscrete pieces ofproduct, such as metalstamping.


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CONTINUOUS PROCESS Equipment operates in a single,

constant state and performs onededicated function.

The process rarely shuts down.

The goal is to produce a

consistent product, no matterhow long the process operates.

Examples of Continuous Processes:

Float Glass Line

Cement Kiln

Combustion Control

Water or Wastewater TreatmentPlant


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BATCH PROCESS Consists of a sequence of one or more steps

in a defined order. Finite quantities of raw materials

processed by the equipment to

produce finite quantities of finished

products.

If more product is to be created, theprocess must be repeated.

The goal is to produce a consistent productthrough repeatability, batch to batch.

Examples of Batch Processes:

Production of beer, ice

cream, and other food products.


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HARD WIRED RELAY

BASED SYSTEMS The contactor and Relays together with

hardware timers and counters were used inachieving the desired level of automation.

DRAWBACKS:

Relays had limitations as control devices:

Controlled on/off type of operations, whilemanufacturing and process equipment werebecoming more sophisticated

Hardwired - changes in industrial andmanufacturing operations requiredequipment modifications and rewiring

Took up space - bulky


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COMPARISON

MICROPROCESSOR A multipurpose,

programmable devicethat accepts digitaldata as input,processes it

according toinstructions stored inits memory, andprovides results asoutput.

It is only onecomponent of anelectronic device andrequires additionalcircuits, memory andfirmware or software

before it canfunction.

MICROCONTROLLER Microcontroller has

a microprocessor,in addition with afixed amount ofRAM, ROM and

other peripheralsall embedded on asingle chip.

A microcontroller isa specialized formof microprocessorthat is designed tobe self-sufficientand cost-effective.

PLC A PLC is a special

microcontroller

designed for

industrial use, that

is for controlling

machinery or

processes.

A PLC is a system

that uses a

microprocessor or

microcontroller as

one of the

components


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PROGRAMMABLE LOGIC

CONTROLLER

A PLC is a microprocessor based, mini-computer

specifically tailored specifically for certain control

tasks.

It uses programmable memory to store

instructions and specific functions that include

On/Off control, timing, counting, sequencing,

arithmetic and data handling to control machinesand processes.


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PROGRAMMABLE LOGIC

CONTROLLER

Extensive use of PLCs because of:

Flexible

Faster Response time Less and simpler wiring

Modular design easy to repair and troubleshoot

Rugged can withstand harsh industrialsurroundings


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HISTORY OF PLC

The first PLC systems evolved from conventionalcomputers in the late 1960s and early 1970s.

Programmable logic controllers were initiallyadopted by the automotive industry where

software revision replaced the re-wiring of hard-wired control panels when production modelschanged.

The plants had to be shutdown for up to amonth at model changeover time but the early

PLCs when used along with other new automationtechniques shortened the changeover time.


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HISTORY OF PLC

The earliest PLCs were developed to offer thesame functionality as the existing relay logic

systems.

The PLCs:

Could start in seconds

Could bear tough plant environment

Had battery backup


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GENERAL FEATURES OF

A PLCGeneral characteristics of a programmablecontroller include:

Withstands rugged industrial environment,

such as temperature and humidity Easily installed and maintained

Reusable (i.e., can be moved andreprogrammed)

Modular (i.e., parts can be replaced easilyfor maintenance or repair)

Easy transition for people who worked withrelays


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COMPONENTS OF

PROGRAMMABLELOGIC CONTROLLERS


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COMPONENTS OF PLC


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COMPONENTS OF PLC

CPU module compresses of the processor and the

memory.

PLC takes information from inputs and makes

decisions to energize or de-energize outputs.- A wide variety of types are available

The PLC power supply converts AC power into DC

power to support those components of the PLC.

The Rack enables data exchange with I/O modules.


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APPLICATIONS OF PLC


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TYPICAL PLC APPLICATION

Here we can see an example of a typical PLC(Programmable Logic Controller) application. Thisapplication could be production of any liquid product,such as the brewing of a batch of beer. What we see

are several devices that can detect information aboutthe beer. The sensors are an example of this-- theycan detect whether the tank is filled too much, or toolittle. We call these devices Input Devices.


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We can also see devices that can create actions to thebatch of beer, such as the motor, that can turn on andmix the beer, or the valves that can open or close, toeither allow beer ingredients to fill the tank, or to allow

the batch of beer out of the tank to the next stage ofthe system. We call these devices Output Devices.

TYPICAL PLC APPLICATION


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ADVANTAGES OF PLCs

FLEXIBILITY

It is easier to create andchange a program in aPLC than to wire and

rewire a circuit. The program can be

modified by the end-useron field.

Moreover, one model of aPLC can be used to runnumerous machines withdistinct program for each

machine.


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LOWER COST

With day-by-dayimproving

technology, it ispossible to getmore functions(relays, timers,

counters,sequencers ) intosmaller and lessexpensivepackages.

ADVANTAGES OF PLCs


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CAPABILITY OFCOMMUNICATION

PLCs can be

communicated toperform functions suchas: supervisorycontrol, datagathering, monitoringdevices and processparameters, anddownloading anduploading of programs.

ADVANTAGES OF PLCs


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QUICK RESPONSE TIME

PLCs have real-timeoperation which implies

that they reactimmediately on the inputthey obtain.

Real-time operation is a

relative concept thatmeans any task isguaranteed to be handledwithin a certain time.

ADVANTAGES OF PLCs


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COMPONENTS OF PLC

There are five basic components in a PLC system:

The PLC processor, or controller

I/O (Input /Output) modules

Chassis or backplane Power supply

Programming software that runs in a PC

In addition to these 5, most PLCs also have:

A network interface


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Stores the control program anddata in its memory

Reads the status of connected

input devices Executes the control program

Commands connected outputsto change state based on

program execution For example: Turn a light on,

start a fan, adjust a speed, ortemperature

Comes in various physical forms

PROCESSOR, CONTROLLER,

OR CPU


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Comes in various physical forms:

PROCESSOR, CONTROLLER,

OR CPU


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I/O MODULES

Physically connect to field devices

Input modules convert electrical signals comingin from input field devices such as pushbuttons,to electrical signals that the PLC can understand.

Output modules take information coming fromthe PLC and convert it to electrical signals theoutput field devices can understand, such as amotor starter, or a hydraulic solenoid valve.

I/O modules form the interface by which inputfield devices are connected to the controller.


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I/O comes in various forms:

I/O MODULES


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TYPES OF I/O MODULES

The following table illustrates four different I/Omodule types and their specific functions:


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I/O CONFIGURATION:

TYPES

Local, Extended-local, and Remote I/Oare terms used for different types of I/O

configurations. I/O configurations aredifferentiated by the following:

The number and type of modules present inthe chassis

The distance of each chassis and modulefrom the processor

The required speed of communications


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LOCAL I/O

Local I/O: I/Omodules connected

to a processoracross a backplane,thus limiting theirdistance from theprocessor.

Resident I/OChassis: Chassisthat houses theprocessor.


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Local I/O configuration:

I/O modules and the processor reside in

the same chassis. I/O modules are connected to the processor

across the backplane.

LOCAL I/O


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EXTENDED-LOCAL I/OExtended-Local I/O: I/O modules connected to

a processor across a parallel link, thus limitingthe distance from the processor.

Parallel Link: A communication link that allowsinformation to transfer simultaneously.

Adapter Module: A module in an I/O chassisthat provides a communication interface betweenthe I/O modules in that I/O chassis and theprocessor.


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Extended-local I/O configuration: I/O modules reside in a separate chassis

from the processor.

An extended-local I/O adapter module and

a multi-conductor cable are needed tocommunicate.

The chassis is generally located closer tothe processor than with remote I/Oconfiguration.

The parallel link to the processor provides afaster data transfer than a serial link.

EXTENDED-LOCAL I/O


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REMOTE I/O

Remote I/O: I/O modules connected to aprocessor across a serial link.

Serial Link: A communication link that allowsinformation to transfer sequentially.


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Remote I/O configuration:

I/O modules reside in separate chassisfrom the processor.

A remote I/O adapter module is needed tocommunicate.

The chassis generally can be located fartherfrom the processor than with extended-local configuration.

Serial link gives a slightly slower data

transfer than extended-local configuration. The distance from the processor (cable

length) depends on the type ofprogrammable controller and the

communication rate.

REMOTE I/O


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CHASSIS/BACKPLANE

All PLCs need some method of communicatingbetween the controller, I/O and communicationsmodules.

A chassis provides the following:

Communication pathways between I/O modulesand processor (or other communications adapter)via a circuit board called the backplane

Power supply connections


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CHASSIS AND BACKPLANE

EXAMPLES


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POWER SUPPLY

A power supply is needed to provide power to thePLC and any other modules.

The Power Supply also furnishes the following:

Conditions voltage and current so that they arecompatible with processor and I/O components

Provides over and under voltage protection

Provides over current protection


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FORMS OF POWER SUPPLIESPower supplies come in various forms: Power supply modules that fit into one of the slots in

a chassis

External power supplies that mount to the outside of

a chassis

Stand alone power supplies that connect to the PLC

or I/O through a power cable

Embedded power supplies that come as part of the

PLC block.


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INTRODUCTION TO FIELD

DEVICES & TYPE OF I/Os


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I/O SYSTEMSI/O systems are often referred to as local ordistributed.

LocalI/Orefers to the I/O being attacheddirectly to the Controller or on the samebackplane as the Controller

DistributedI/Orefers to I/O which is not on

the same backplane as the Controller.Distributed I/O is connected using a network.

The distributed input module sends the inputs across thebackplane to the adapter.

The adapter sends them over the I/O network to the PLC(Controller).

LOCAL DISTRIBUTED I/O


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LOCAL vs. DISTRIBUTED I/O

SYSTEM Why use Local I/O?

Faster than distributed I/O Easy to install - add a module to the chassis Less expensive than adding distributed

Why use Distributed I/O? Field devices distributed around the machine -

too much wiring to take back to one chassis Out of local I/O

local I/O limited by number of slots in thebackplane or fixed I/O attached to theprocessor

Local I/O does not meet your needs

module type, current capability, etc.


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INPUT MODULES Input modules interface directly to devices such

as switches and temperature sensors. Input modules convert many different types of

electrical signals such as 120VAC, 24VDC, or 4-20mA, to signals which the controller canunderstand.


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Input modules convert real world voltage andcurrents to signals the PLC can understand.

Since there are different types of input devices,there is a wide variety of input modules available,including both digital and analog modules.

INPUT MODULES


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DISCRETE vs. ANALOG

MODULESDiscrete Modules Digital Modules)

Devices that are either on or off, such as apushbutton, get wired to discretemodules.

Discrete modules come in a variety of types, suchas 24VDC or 120VAC, and allow you to typicallyconnect anywhere from 2 to 32 devices, with themost popular being 16 devices.

Since it takes only 1 bit to represent the state of

a device, a 16 point discrete module onlyrequires 16 bits of memory in the controller tostore the states of all the points on the module.


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Output modules take a signal from a PLC and

convert it to a signal that a field device needs tooperate.

Since there are different types of output devices,there is a wide variety of output cards available,including both digital and analog cards.

OUTPUT MODULES


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ACTUAL WIRING OF

DEVICES TO PLC


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WIRING OF PLC

One of the many advantages to using a PLC/PAC isthe simplicity of the I/O wiring.

I/O devices are wired to I/O points on a fixed I/O

unit and to I/O modules in a modular unit. Input devices such as switches, pushbuttons and

sensors are wired to input module points andoutput devices such as indicator lights, solenoids

and motor starter coils are wired to outputmodule points.


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DEFINITIONSSinking and Sourcing:

Sinking and sourcing areterms to describe acurrent flow relationshipbetween field input andoutput devices in a controlsystem and their powersupply.

Sourcing I/O circuits

supply current to sinkingfield devices.

Sinking I/O circuitsreceive current from

sourcing field devices.


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SINK SOURCE

CONNECTIONS Sink Connections: A sink I/O device or I/O

module will always have a connection to thenegative side of the DC power supply. Thenegative side of the DC power supply is referred

to by any one of or either of the terms: ground,common, DC common, return, DC return, etc. Allthese terms refer to the same electrical point;the negative side of the DC power supply. Sink isdesignated NPN.

Source Connections: A source I/O device or I/Omodule will always have a connection to thepositive side of DC power supply. The positiveside of the DC power supply is referred to as

VDC+, positive, etc. Source is designated PNP.

WIRING OF PLC SINK &


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It is method of connecting two different polarity signalto a common terminal. It may be of two types1. Input wiring

a. sinking configurationb. sourcing configuration

2. Output wiringa. sinking configurationb. sourcing configuration

WIRING OF PLC SINK &

SOURCE

SINK SOURCE


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SINK SOURCE

CONNECTIONS

Source & Sinking is used exclusively withDigital DC circuits. If the common pin is +polarity, its called a sourcing circuit. If itspolarity, its called a sinking circuit.

Advantages: No moving parts, so lifespan is longDisadvantages: No AC support. Cant handle

significant current.


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SCAN CYCLE OF PLC

SCAN CYCLE OF PLC PLC


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SCAN CYCLE OF PLC PLC

OPERATIONA PLC works by continually scanninga program.We can think of this scan cycle as consisting of 3important steps.

The Scan Time, the time required for one fullcycle, provides a measure of the speed of

response of the PLC.


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PROCESSOR SCANNING1. Input Scan: The state of the inputs is recorded in

the input image table.

The PLC records this data into its memory to beused during the next step.

This makes the PLC operation faster, and avoids

cases where an input changes from the start to theend of the program (e.g., an emergency stop).

2. Program Scan:

The input image data table is examined & the

program logic is executed.

The data is changed in accordance with theprogram and output image table is prepared.

The information does not go to actual outputs.


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PROCESSOR SCANNING

3. Output Scan:

The output table is copied from memory to theoutputs. These then drive the output devices byproviding 0 or 1 logic.

In this way, the information stored in the outputimage table is used to switch output devices.

SYNCHRONOUS &


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SYNCHRONOUS &

ASYNCHRONOUS SCAN

Synchronous and asynchronous scan is oneexample of a variation among I/O andcommunication interfaces.

A synchronous interface begins the I/O-device update only when the processorcommunicates with the interface.

An asynchronous interface, on the otherhand, scans the I/O devices on acontinuous basis - independent ofprocessor communication with the interfaceboard.

CONTINUOUS PERIODIC


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Executes each programtop to bottom and thenrestarts

Operates at the lowestpriority on the controller

Uses all CPU time leftafter other tasksexecute

Interrupted by operatingsystem to performprocessor andcommunicationsoverhead

Traditional PLC Scan

Triggered automaticallyat a preset time interval

Interrupts lower prioritytasks and can beinterrupted by higherpriority tasks (15 Levels)

Will share time (on a1ms basis) with othersame priority level tasks

Captures fault for taskoverlap

Similar to PLC/SLCSelectable Timed

Interrupt (STI)

SCANPERIODIC

SCAN

CONTINUOUS PERIODIC


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SCANPERIODIC

SCAN

INTERRUPTS


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INTERRUPTSInterrupt function. It is an event that interrupts

the scan to process a special routine that you havewritten.

In simpler terms, this means that as soon as theinput turns on, regardless of where the scan

currently is, the PLC immediately stops what itsdoing and executes an interrupt routine.

A routine can be thought of as a mini programoutside of the main program.

An interrupt must be configured and enabled toexecute.

After its done executing the interrupt routine, itgoes back to the point it left off at and continueson with the normal scan process.

INTERRUPT PRIORITY


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INTERRUPT PRIORITY When there are more than one interrupt occurred at the same

time, only the interrupt with highest priority can be executed.

All the other interrupt routines need to wait until it became thehighest priority among the pending interrupts.

Consequently, a response delay of hundreds of microseconds,or even few milliseconds, may be caused. Hence, in a multipleinterrupt inputs structure, an interrupt priority is given to eachinterrupt in accordance with its importance.

INTERRUPT PRIORITY


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If another interrupt request is made when the

PLC is carrying out a higher priority interruptservice routine than the new interrupt request, theCPU will wait until the execution of the subroutineis completed before accepting the new interrupt

request. However, if the priority of the new interrupt

request is higher than the one being executed, theCPU will stop the running of the current interrupt

service routine immediately to execute theinterrupt service routine with a higher priority.

After completing the execution, the CPU will returnto the previously interrupted service routine with alower priority to continue the incomplete work.

INTERRUPT PRIORITY


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REDUNDANCY

In engineering, redundancy is the duplication ofcritical components or functions of a system withthe intention of increasing reliability of thesystem, usually in the case of a backup or fail-

safe. Redundancy: Many PLCs are capable of being

configured for redundant operation in which oneprocessor backs up another.

This arrangement often requires the addition of aredundancy module, which provides statusconfirmation and control assertion between theprocessors. In addition, signal wiring toredundant racks is an option.

REDUNDANCY OBJECTIVE


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REDUNDANCY OBJECTIVE To improve the amount of up-time of a

machine or process by ensuringconsistent availability of that machine.

This also reduces costs associated

with equipment failure

To guard against system shutdown, aredundant system must provide:

equipment with exceptional reliability

automatic fault isolation

minimal disturbance of the process

when switching from the primary

to the secondary system

IMPORTANT TERMS IN A


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IMPORTANT TERMS IN A

REDUNDANT SYSTEM

S O C


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TYPES OF REDUNDANCY

Redundancy in PLCs can be of two types:

Hardware, and/or

Software Redundancy.

Hardware redundancy Refers tosecondary controllers, secondary chassis,redundant power supplies, I/O s, present totake control of primary hardware in timesof failure.

Software redundancy- Refers tosecondary programming software,communication software present to takecontrol in times of software failure.


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LEVELS OF


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Redundancy solutions are available at all levelsincluding; power supply, communication interfacesand I/O circuits.

LEVELS OF

REDUNDANCY


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INDUSTRIAL NETWORKS


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REASONS TO USE A


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REASONS TO USE A

NETWORK There are many reasons to use a network. Some

examples are:

Data Acquisition from the Control System

Control devices in a remote location

Data Sharing Between PLC Controllers

The ability to program devices from a remotelocation

The ability to troubleshoot problems from aremote location

The ability to integrate manufacturing systemswith business system

Examples of networks used in industrial automationtoday are

EtherNet/IP, ControlNet, DeviceNet, DH+, RemoteI/O, Foundation Fieldbus, Profibus DP, Modbus.


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TYPES OF NETWORKS


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Device Network Typical devices are field devices such asbuttons, lights, valves, and drives. Alsosmall blocks of I/O.

Common use is for direct connection to field

devices. Sensor

Typical devices are very simple field devicessuch as sensors, and lights.

Common use is for direct connection to field

devices

TYPES OF NETWORKS

NETWORK FUNCTIONS


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NETWORK FUNCTIONS

NETWORK FUNCTIONS


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Rockwell Automation connects to a number of networks

to support control, configure, and collect activities ControlNet

DeviceNet

Ethernet/IP

Remote I/O (RIO)

DH+

DH-485

Other competitive Also serial communications using DF1 protocol

For Process applications to interface to instrumentation

Foundation Fieldbus

HART

NETWORK FUNCTIONS

FUNCTIONS THEY PROVIDE


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FUNCTIONS THEY PROVIDE

DF1


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DF1

A serial protocol for RS-232 Typically point-to-point, two nodes (full

duplex)

Designed for A-B PLCs to communicate

over modems.

RIO (R t I/O)


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RIO (Remote I/O)

An I/O control network, used by PLCs. Optimized for scanning a known amount ofI/O in a very predictable fashion Deterministic

Media: PVC Twinaxial cable (w/shield)Blue hose Daisy-chain between nodes Data Rates: 57.6k, 115.2k, 230.4k baud

Max Distance: 10,000 ft. (30 miles via fiberoptic repeaters) Topology: Master/Slave Max Nodes: 32

DH+ (DATA HIGHWAY PLUS)


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DH+ (DATA HIGHWAY PLUS)

A messaging network for PLCs.

Allows access to PLC data table info via read orwrite messages (PCCC)

Protocol: a token passing Peer to Peer busnetwork.

Number of Stations: 64 stations maximum

15 or less recommended.

Cable System: Twin axial Baseband (Blue Hose)

Provides online programming capability

57.6 Kbaud ----> 10,000 ft.

115.2 Kbaud ----> 5,000 ft.

230.4 Kbaud ----> 2,500 ft.

DH485


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DH485 An information network primarily designed for

SLC500, 5/02, 5/03 A token passing Peer to Peer bus network up to

19.2 Kbaud

Number of stations: 32 maximum / 15 or less

recommended Often requires more hardware to support network

connections (i.e.. AIC Link Coupler) vs. DH+

Message passing network only, not deterministic.

Supports a respond only mode for low level devices Remote programming support

Based on RS-485 electrical signal specification


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DEVICENET


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DEVICENET Lower Acquisition and Installation Cost

Reduction in plant wiring (eliminates hardwiring of I/O) Lower installation, start-up, and maintenance times

Network Attributes Data flow is governed by the Producer/Consumer model Ability to link smart factory floor devices together and

bridge to higher level networks Superior device level diagnostics Device Plug and Play capabilities - add or remove nodes

on the fly 64 devices per network and data rates of 125, 250, and

500KB Media Options Passive bus media: nodes can enter and leave without

affecting the network Sealed (IP67) and unsealed (IP65) media

Low cost flat media


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ETHERNET/IP


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Connectivity to all computer manufacturers and software Standard network management software: SNMP Highly efficient data transfer

Increased baud rates (10Mb, 100Mb), use of switches(instead of hubs), full duplex data transmission to

minimize effect of message collisions, and isolationfrom the office Ethernet network Use of commercial off the shelf products and technology

Common set of installation and support tools Well established network standard, Can take

advantage of web browsing services in the products Media Options Active bus media: supports star network topologies High noise immunity (fiber optic cabling) Extend bus length with multiple switches (copper

and fiber)

ETHERNET/IP

HOW THESE NETWORKS


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HOW THESE NETWORKS

DIFFER

FOUNDATION FIELDBUS H1


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FOUNDATION FIELDBUS H1

Digital network designed specifically to supportthe demands of devices used in a processapplication.

Device communication is scheduled at specific

intervals Control, such as loop functions, can be

distributed among the devices. Devices haveembedded function blocks.

Devices are capable of transferring largeamounts of analog data, in addition to digitaldata.

Foundation Fieldbus H1 is an open protocol

developed in the 1990s.

HART


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HART Digital signals encoded on the analog signal

providing additional diagnostic data from thetransmitter

Can be used in traditional 4-20mA applications andis backward compatible with existing installations.

HART was the first open protocol to connect analogdevices together

Millions of devices installed worldwide

80% of all Instruments sold today have HARTconnectivity

Many customers dont use it, but devicemanufacturers build it in to almost all devicesrather than making HART and non-HART devices.

PROTOCOL CONVERTER


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PROTOCOL CONVERTER It is a device used to convert standard

protocol of one device to the protocol suitable forthe other device or tools to achieve theinteroperability.

Protocols are software installed on the routers

which convert the data formats, data rate andprotocols of one network into the protocols ofthe network in which data is navigating.

GENERAL ARCHITECTURE


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OF A PROTOCOL

CONVERTERIt includes an: internal master protocol - communicating to the

external slave devices and the data collected is

used to update the internal database of theconverter.

When the external master requests for data, theinternal slave collects the same from the

database and send it to the external master. There will be different schemes for handling the

spontaneous reporting of events and commands.

PROTOCOL CONVERTER


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Protocol Converters are generally used for

transforming data and commands from one device orapplication to another.

This necessarily involves transformation of data,commands, their representation, encoding and

framing to achieve the conversion. The simplest and most commonly used conversion is

protocol conversion between Modbus RTU andModbus TCP.

PROTOCOL CONVERTER


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WIRELESSCOMMUNICATION

WIRELESS TECHNOLOGY


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WIRELESS TECHNOLOGY

Industrial Wireless Technologies Technology Based on Spread Spectrum

Introduction to Spread Spectrum

Spread Spectrum vs. Narrow Band

Technology Frequency Hopping Spread Spectrum

Direct Sequence/OFDM

RF Bands - 900 MHz, 2.4 GHz, 5 GHz

Future Technology

BASIC INDUSTRIAL


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WIRELESS TECHNOLOGY

RADIO TYPES Analog vs. Digital

Some video/voice use analog

Spread spectrum radios such

as RadioLinx are digital Receiver

Receives signal - does notintentionally transmit a signal

Like FM or XM music receiver

Transmitter

Transmits signal only

Generally lower cost part of aradio

Separate transmitter /receiver systems

Communication is singledirection

Common for telemetry of aanalog or digital signal

Low cost transmitters onremotes, fewer receivers

Transceiver (RadioLinx)

Single radio sends andreceives signals

Receiver can ask or request toresend message

BASIC INDUSTRIALWIRELESS


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WIRELESS

TECHNOLOGIES UHF / VHF Licensed radios (Narrow Band) 220 MHz, 450 MHz & 900MHz

Unlicensed ISM band (FHSS, DSSS, OFDM)

Spread spectrum

900 MHz (902MHz to 928MHz 26 MHz of Bandwidth) 2.4 GHz (2.4GHz to 2.4835GHz 83.5 MHz of Bandwidth)

5.8 GHz

IEEE 802.11 (WiFi)

IEEE 802.11a, b, g and n

2.4 GHz (b/g), 5.8 GHz (a)

802.15 short range

Bluetooth

Zigbee

802.16 (WiMax)

GSM / GPRS cellular

Satellite ( GEO, LEO, MEO)

MOST POPULAR AND


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EMERGING TECHNOLOGIES

WIRELESS TECHNOLOGIES


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RECOMMENDED

APPLICATIONS*

TECHNOLOGY BASED ONSPREAD SPECTRUM


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SPREAD SPECTRUM

INTRODUCTION TO SPREADSPECTRUM Spread spectrum

a class of modulation techniques that spreads a signals

power over a wider band of frequencies than is necessaryfor the information being transmitted

Spreads the RF energy across the RF spectrum

Benefits of spreading the signal:

Signal is more immune to unwanted noise / interference Simultaneous transmission of multiple signals within the

same frequency band

Provides inherent data encryption / security

Supports fast data rates

NARROWBAND VS.


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SPREAD SPECTRUM Narrow band (VHF)

License required

Long range

Line-of-sight not

required

Slow data rates

Spread Spectrum

License free

Long range in somesituations

Line-of-sight critical

High speed capable


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INDUSTRIAL WIRELESS


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TECHNOLOGIES SHORT RANGE

(802.15.1 BLUETOOTH)

802.15 Wireless Personal AreaNetwork (WPAN)

2.4 GHz FHSS fast hopping(1600 hops/s)

Class 3 - 1 mW ~ 10m

Class 2 - 2.5 mW ~ 20m

Class 1 - 100 mW ~ 100m

720 kbits/s (less w/ ForwardError Correction FEC)

FUTURE INDUSTRIALWIRELESS TECHNOLOGIES


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WIMAX (802.16 STANDARD

75MBPS TO 10 KM) Fixed WiMax - 2.5GHz and 3.5 GHz Requires License

Fixed WiMax 5.8 GHz license free

Informationgatheredfrom

//www.wimax.com/education

FUTURE INDUSTRIAL


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CELLULAR (GSM & CDMA)

1G, 2G and 3G Cellular refers to generation of wireless

Monthly Charges depending on the frequency of data

Coverage Depends on the Carrier (Verizon, AT&T, etc.)


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INTRODUCTION TO PLC

PROGRAMMING

PLC PROGRAMMING


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PLC PROGRAMMINGEvery PLC has associated programming software that

allows the user to enter a program into the PLC.

Software used today is Windows based, and canbe run on any PC.

Different products may require differentsoftware: PLC5, SLC, and ControlLogix each

require their own programming software.

Example of PLC programming software


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PLC PROGRAMMING LADDER LOGIC


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LADDER LOGIC

Each line of code is known as a rung. In this examplethere are 4 rungs, numbered 0, 1 and 2, and the end rung

marking the end of the program. The PLC executes the program 1 rung at a time, starting

with the first rung and then working down. Ladder logic rungs are basically IF-THEN statements. Each

individual rung is executed from the left to the right


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PRODUCED / CONSUMED


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TAGS Multiple Logix controllers in the same backplaneor connected via Ethernet/IP or ControlNet may

share tag data values

No code or message instructions required topass values

Consumed tag can be used to trigger anEvent Task in a controller

Data may be scheduled between processorssimilar to I/O operation

Simple configuration of tag settings Mark a tag as a produced and point consumed

tags in remote controllers to it

Select the requested packet interval orbroadcast rate as fast as 1msec


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BASIC INSTRUCTIONS


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One organizes ladder logic as rungs on a ladder

and put instructions on each rung. There are twobasic types of instructions:

Input instruction: An instruction that checks,compares, or examines specific conditions in the

machine or process. Output instruction: An instruction that takes

some action, such as turn on a device, turn off adevice, copy data, or calculate a value.

BASIC INSTRUCTIONS


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EQUIVALENT LADDER LOGIC

DIAGRAM


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DIAGRAM

TIMERS


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TON Timer On Delay

Count time base intervals whenthe instruction is true.

TOF Timer Off Delay

Counts time base intervals

when the instruction is false. RTO Retentive Timer

Counts time base intervalswhen the instruction is true

and retains the accumulatedvalue when the instructiongoes false or when power cycleoccurs.

COUNTERSCTU C t UP


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CTU Count UP

Increments the accumulated value

at each false to true transition andretains the accumulated valuewhen the instruction goes false orwhen power cycle occurs.

CTD Count Down Decrements the accumulate value

at each false to true transition andretains the accumulated value

when the instruction goes false orwhen power cycle occurs.

RES Reset

Resets the accumulated value and

status bit of a timer or counter.

FILE INSTRUCTIONS


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1. FFL - First In, First Out (FIFO) Load

On a false-to-true rungtransition, the First in First out Load

(FFL) instruction loads words

or long words into a

user-created file called

a FIFO stack.

2. FFU First In, First Out (FIFO)

UnloadOn a false-to-true rung transition,

the FFU instruction unloads words

Or long words from a user created

file called a FIFO stack.

FILE INSTRUCTIONS


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3. LFL - Last In, First Out (LIFO) Load

On a false-to-true rungtransition, the LFL instruction

loads words or long words

into a user-created file called

a LIFO stack.

4. LFU Last In, First Out (LIFO) Unload

LIFO unload (LFU), is

paired with a given LFLinstruction to remove

elements from the LIFO

stack.

COMPARISON

INSTRUCTIONS


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INSTRUCTIONS1. EQU Instruction

When source A and source B are

equal, the instruction is logically

true. If these values are not

equal, the instruction is logicallyfalse.

2. NEQ Instruction

When source A and source B are not

equal, the instruction is logicallytrue.

Here, Source A must be an address.

Source B can be either a

ro ram constant or an address.

COMPARISON

INSTRUCTIONS


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3. LES Instruction

When source A is less than the

value at source B, the

instruction is logically true.

4. LEQ Instruction

When the value at source A is less

than or equal to the value at

source B, the instruction is

logically true. Here, Source A must be an

address. Source B can be

either a program constant or an address.

INSTRUCTIONS


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COMPARISON

INSTRUCTIONS


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7. LIM Instruction

It tests for values within or outside aspecified range, depending on how thelimits are set.

The Low Limit, Test, and High Limit value

are restricted to the followingcombinations:

If the parameter is a program constant,both the Low Limit and High Limit

parameters must be word addresses.If the parameter is a word address, theLow Limit and High Limit parameters canbe either a program constant or a word

address

INSTRUCTIONS


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CONTROLLER


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A controller compares the actual value of outputwith the reference input, determines thedeviation, and produces a control signal that willreduce the deviation to zero or to a small value.

The manner in which the controller produces thecontrol signal is called the control action.

PID CONTROLLERPID stands for:


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PID stands for:

P (Proportional)

I (Integral)

D (Derivative)

These controllers have proven to be robust and extremelybeneficial in the control of many important applications.

It provides the most accurate and stable control and isbest used in systems which have a relatively smallmass and those which react quickly to changes in theenergy added to the process.

PID CONTROLLER

CHARACTERISTICS


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CHARACTERISTICSPID controllers are process controllers with the

following characteristics: Continuous process control Analog input (also

known as "measurement" or "Process Variable" or"PV")

Analog output (referred to simply as "output") Set point (SP)

Proportional (P), Integral (I), and / or Derivative(D) constants

Proportional Band is referred to as Gain

Integral Band is referred to as Reset

Derivative Band is referred to as Rate

When an error is introduced to a PID controller

PID CONTROLLER


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When an error is introduced to a PID controller,the controllers response is a combination of

the proportional, integral, and derivativeactions, as shown in Figure below.

PID CONTROLLER


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Proportional Band is referred to as Gain

Integral Band is referred to as Reset

Derivative Band is referred to as Rate

When an error is introduced to a PID controller the

PID CONTROLLER


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When an error is introduced to a PID controller, thecontrollers response is a combination of the

proportional, integral, and derivative actions, asshown in Figure below.


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FUZZY CONTROL


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Fuzzy logic is well suited to implementing

control rules that can only be expressedverbally, or systems that cannot be modeledwith linear differential equations. Rules andmembership sets are used to make a decision.

Fuzzy Logic Control (FLC) or sometimes knownas Fuzzy Linguistic Control is a knowledge basedcontrol strategy that can be used- when either a sufficient accurateand yet not

unreasonably complexmodel of the plant is

unavailable, orwhen a (single) precise measure ofperformance is not meaningful or practical.

EXAMPLE OF FUZZY

CONTROL


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CONTROL

An example of a fuzzy logic controller forcontrolling a servomotor is shown in Figure. Thiscontroller rules examines the system error, andthe rate of error change to select a motorvoltage. In this example the set memberships aredefined with straight lines, but this will have aminimal effect on the controller performance.

TYPES OF FUZZYCONTROLLERS:


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CONTROLLERS:

- DIRECT CONTROLLERThe Outputs of the Fuzzy Logic System Are the

Command Variables of the Plant:

TYPES OF FUZZY

CONTROLLERS


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CONTROLLERS:

- SUPERVISORY CONTROLLERFuzzy Logic Controller Outputs Set Values forUnderlying PID Controllers:

TYPES OF FUZZYCONTROLLERS:


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CONTROLLERS:

- PID ADAPTATIONFuzzy Logic Controller Adapts the P, I, and DParameter of a Conventional PID Controller:

ALARMS AND EVENTSMANAGEMENT


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MANAGEMENT

- DEFINITION In the process control industry, the terms alarmsand events are used to describe occurrences in aprocess plant which have a certain meaning. Ininformal conversation, the terms alarm and eventare often used interchangeably and their meaningsare not distinct.

An alarm is an abnormal condition that requiresspecial attention.

An event may or may not be associated with acondition.

Alarm and event management can help eliminatethe issues traditionally associated with alarming.

ALARMS AND EVENTS Alarms represent warnings Events represent


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Alarmsrepresent warningsof process conditions that

could cause problems, andrequire an operator response.

A typical alarm is triggeredwhen a process value exceeds

a user-defined limit. Thistriggers an unacknowledgedalarm state which can beused to notify the operator of

a problem. Once the operatoracknowledges the alarm, thesystem returns to anacknowledged state.

Events representnormal system status

messages and do notrequire an operatorresponse. A typicalevent is triggered

when a certain systemcondition takes place,such as an operatorlogging.

BENEFITSWith installed Alarms and Events management softwaresthat come along with the software package:


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that come along with the software package:

Alarm instructions are programmed only once, and thendownloaded to the controller, reducing programmingeffort and errors.

Alarm conditions are detected more quickly and real-time alarming is performed in the controller.

HMI tags or alarms in Server are not required, reducingoverhead and tag mapping errors.

Alarm state is managed, processed, and preserved bycontrollers, even if the computer falters.

Alarm status is communicated only when state changes,reducing network overhead, controller processing, andimproving overall system performance.

Time stamps on alarm conditions are accurate,and not

delayed until they reach the Alarm and Event Server


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