P L C in industrail automation

8/10/2019 P L C in industrail automation

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DEPT. OF ELECTRONICS AND AUTOMATION

NALCO E&A

(A Govt. of India Enterprise)

RISHIJIT PANIGRAHI1041110289ECE E

4TH

YEAR


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NALCO OVERVIEW

Incorporated in 1981ISO 9002 (QMS)

ISO14001(EMS).

Miniratna status.

Largest integrated

Aluminium plant in Asia


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Units

ALUMINAREFINERYBAUXITEMINES

SMELTER CAPTIVE POWER PLANT HOME


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BAUXITE MINES

Koraput Panchpatmalihills

48 ltpa

Open cast mining

( Computerised mine planning)Gibsite bauxite (Al2O3.3H20)

14.6 km long single flight, multi

curve cable belt conveyor of

1800 tph capacity.

HOME


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d

ALUMINA REFINERY

One among top ten in worl

15.75 ltpa of calcined alumina

Atmospheric digestion at low

temperatureBayers process

Distributed

controldigital process


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T

HOME

CAPTIVE POWER PLAN

960 MW Capacity (8x120MW)

Microprocessor-controlled burner

management, Computerised

DAS, automated turbine run-up,brush less excitation of

generators, islanding facility.

7th 8th DCS in and units.


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-IALUMINIUM SMELTER

180 KA cell technology ofAluminium Pechiney France

Hall-Herauolt electrolysis process.

Integrated

3.45ltpa of

3 pot-lines

Aluminium plant

Aluminium. with

240electrolytic pot shell each.

I


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CAST HOUSE

Cast house

Strip casting plant

CARBON AREA

Green anode plant

Bake oven furnaceRodding shop Rolled

unitproducts

ALUMINIUM

SMELTER

POT LINES

Pot regulation system

Fume treatment plant

Alumina handling

system


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POT LINES

FumetreatmentplantPotregulationsystem

Alumina handling ystem

HOMELaddle and pipecleaningshop


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SYSTEM

ROOM

Anodes

connected

in

parallel(1

6)

POT REGULATIONElectrolytic pot cell connected in

-A

series

1050180

KA

V

Cathode is

carbon bar

+Aluminiu

m metal

ROOM-

BHOME

-

+

A001A120

B001 B120


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POT REGULATION SYSTEMSERVER 2

MAN-MACHINE

INTERFACESERVER 1

DIGITAL MULTI-

SWITCHING

DEVICE

Communicator 1 Communicator 2

1 2 3 14 15 16 1 2 3 14 15 16

Group of 15

Electronic pot

micro

controller HOME


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FUME TREATMENTAlumina from

SILO

PLANT

Fluorine gas from

Electrolytic pot

Dry scrubbing infilter reactors CLEAN

GAS

Fluorinated Alumina

to Electrolytic pot

shell HOME


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ALUMINA HANDLING SYSTEM

Transfer of alumina through

Bottom air fluidisation

Storage of alumina in PrimarySILO (6 no. each

Supply to

FTPs as quantity.

of 13,500 t)

per required

HOME


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RedundantRACKS

SYSTEM CONFIGURATION Man -ProcessInterface

PC-PLC

Communication

I/O

processors

HOME


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PROGRAMMABLE

LOGICCONTROLLER


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Early control systems consisted of huge control boards consisting ofhundreds to thousands of electromechanical relays.

An engineer would design the system logic, electricians would receivea schematic outline of logic then implement the logic with relays.

The schematic was commonly called LadderSchematic

The ladder displayed all switches, sensors, motors, valves, relays etc inthe system.

Problems: Long commissioning time, dependency on mechanicalreliance, Any system logic design change required the power to thecontrol board to be isolated stopping production.

History


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General Motors was among the first to recognize a need to replacethe systems wiredcontrol board

Hydramatic Division of GM specified the design criteria for theprogrammable controller in 1968.

Goal Eliminate the high cost associated with inflexible, relay

controlled systems.

History


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New Controller Specifications:

Solid State System Computer Flexibility

Operate in Industrial Environment (vibrations, heat, dust etc.)

Capability of being reprogrammed

Easily programmed and maintained by electricians and

technicians.

History


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In 1969 Gould Modicon developed the first PLC.

Strength Programmed with Ladder Logic

Initially called Programmable Controllers PCs

Now - PLCs,Programmable Logic Controllers PLCs have evolved from simple on/off control to being able to

communicate with other control systems, provide productionreports, schedule production, diagnose machine and processfaults.

History


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Advantage of PLC Over Relay Style

RELAY PLC

1-Hard wiring 1-Less wiring

2-Changes difficult 2-Easy modification

3-More power 3-Low power

4-More maintenance 4-Less maintenance

5-Difficult to expand 5-Ease of expansion


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Control Systems Types

Programmable Logic Controllers

Distributed Control System

PC- Based Controls


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Sequential logic solver

PID Calculations.

Advanced Subroutines

BIT Operations.

Data Transfer.

Text Handling.


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Applications : Machine controls, Packaging, Palletizing, Material handling, similar

Sequential task as well as Process control

Advantages of PLC :

They are fast and designed for the rugged industrial environment. They are attractive on Cost-Per-Point Basis.

These Devices are less Proprietary ( E.g.. Using Open Bus Interface.)

These Systems are upgraded to add more Intelligence and Capabilitieswith dedicated PID and Ethernet Modules.

Disadvantages of PLC : PLC were Designed for Relay Logic Ladder and have Difficulty with

some Smart Devices.

To maximize PLC performance and Flexibility, a number of OptionalModules must be added

PLC holds only one copy of program



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PLC Types Nano (Small)

Micro (Medium)

Large

Basic criteria for PLC Types

Memory Capacity I/O Range

Packaging and Cost per Point



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Sizing of PLC

Micro PLCs: I/O up to 32 points

Small PLC: I/O up to 128 points

Medium PLC: I/O up to 1024 pointsLarge PLC: I/O up to 4096 points

Very Large: I/O 4096 Onwards


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Most Basic of PLC Systems

In the most basic of PLC systems, a self contained (shoe box) PLC has 2terminal blocks, one for Inputs and one for Outputs

Today, most PLCs in this category are know as Micros. Typically theyprovide front panel LED status indication of I/O and Processor states

InputsOutputs

C

R


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Modular Chassis Based PLCs

The vast majority of PLCs installed today are modular chassis basedsystems consisting of:

1. Processor Module (CPU)

2. Input & Output Modules

3. Chassis

4. Power Supply


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Modular Chassis-less PLC Systems

Also available from many vendors are Chassis less but still ModularPLC systems. These systems still require a Processor, I/O Modules, andPower Supply, but in place of a chassis these components mountdirectly onto a panel, din rail, and many use a tongue and grove system

to allow easy insertion and removal


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Central Processing Unit (CPU)

Input Output Modules

Power Supply Bus system

Programming Device

P L C Components

CPU

PROGRAM

DEVICE

IN OUT m

MODULEMODULE


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Basic PLC Schematic

CPU

Power Supply

Memory Input Blocks

Output Blocks

Communications

Expansion Connections


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It is a micro-controller based circuitary. The CPU consists of

following blocks :

Arithmatic Logic Unit (ALU), Timing / Control ckt, Programmemory, Process image memory (Internal memory of CPU)

Internal timers and counters and Flags, Address stack andinstruction registers

The Central Processing Unit (CPU) Module is the brain of thePLC.

P L C : Central Processing Unit


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CPU Module

CPU performs the task necessary to fulfill the PLC functions. These

tasks include Scanning, I/O bus traffic control, Program execution,

Peripheral and External device communication, special functions ordata handling execution and self diagnostics.

Self

Check

Execute

Code

Scan

Inputs

Update

Outputs

PLC Program

SCAN

Primary role to read inputs, execute the control program, update

outputs.


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Memory

The memory includes pre-programmed ROM memory containing

the PLCs operating system, driver programs and application

programs and the RAM memory.

PLC manufacturer offer various types of retentive memory to save

user-programs and data while power is removed, so that the PLC

can resume execution of the user-written control program as soon as

power is restored.


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Memory

Many PLCs also offer removable memory modules, which are plugged

into the CPU module.

Memory can be classified into two basic categories: volatile and non-

volatile.Volatile memoryloses state (the stored information) when power

is removed.

Nonvolatile memory, maintains the information in memory even

if the power is interrupted.


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Memory

Some types of memory used in a PLC include:

ROM (Read-Only Memory)

RAM (Random Access Memory)

PROM (Programmable Read-Only Memory) EPROM (Erasable Programmable Read-Only Memory)

EEPROM (Electronically Erasable Programmable Read-Only

Memory)

FLASH Memory Compact Flash Can store complete program information, read &

write text files


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I/O Modules

Input and output (I/O) modules connect the PLC to sensors and

actuators.

Provide isolation for the low-voltage, low-current signals that the PLCuses internally from the higher-power electrical circuits required bymost sensors and actuators.

Wide range of I/O modules available including: digital (logical) I/Omodules and Analog (continuous) I/O modules.


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These modules act as link between field input sensors and the CPU.

Analog input module : Typical input to these modules is 4-20 mA,0-10 V, Ohms, mV

Ex : Pressure, Flow, Level Tx, RTD (Ohm), Thermocouple (mV)

Digital input module : Typical input to these modules is 24 V DC,115 V AC, 230 V AC

Ex. : Switches, Pushbuttons, Relays, pump valve on off status

PLC : Input module


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PLC : Input module

Transfer of data:-I/P sensor to CPU

Conversion:- 24vdc/230vac to 5vdc

Isolation :- By Opto Coupler


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Input Devices

Pushbuttons

Selector Switches

Limit Switches

Level Switches

Photoelectric Sensors

Proximity Sensors

Motor Starter Contacts

Relay Contacts

Thumbwheel Switches


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SOURCING vs. SINKING DC Inputs

DC

Power

Supply

Field

Device

DC

Input

Module

+

- DC COM

IN1

C

DC

Input

ModuleField

Device

DC

Power

Supply

+

-

+VDC

IN1

IN1

VDC

SINK SOURCE


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Analogue Inputs/Outputs

Analogue input cards convert continuous signals via a A/D

converter into discrete values for the PLC

Analogue output cards convert digital values in then PLC to

continuous signals via a D/A converter.

Resolution can be important in choosing an applicable card

Example, for a temperature input of 0 to 100 degrees C

For 8 bit resolution the value in the PLC is 0 to 255

For 12 bit resolution the value in the PLC is 0 to 4095 For 12.5 bit resolution the value in the PLC is 0 to 6000




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Analogue Cards

Typical Analogue Input

signals are:

Flow sensors

Humidity sensors

Load Cells

Potentiometers

Pressure sensors

Temperature sensors

Vibration

Analogue Output signalscontrol:

Analogue Valves

Actuators

Chart Recorders Variable Speed Drives

Analogue Meters

Typical Analogue Signal Levels

4-20mA

1-5 Vdc

0-10 Vdc

-10 10Vdc


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PLC : Input module


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These modules act as link between the CPU and the output devices

in the field.

Analog output module : Typical output from these modules is 4-20mA, 0-10 V

Ex : Control Valve, Speed, Vibration

Digital output module : Typical output from these modules is 24 VDC, 115 V AC, 230 V AC

Ex. : Solenoid Valves, lamps, Actuators, dampers, Pump valve on offcontrol

PLC : Output module


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Relay type -For AC or DC

Transistor Type Logic(TTL) -For DC

Triac (Triode AC) type - For AC

Isolated common type -For different device

PLC : Output module - Types


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PLC : Output module


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Output Devices

Valves

Motor Starters

Solenoids

Control Relays

Alarms

Lights

Fans

Horns

Relays

120 VAC/VDC

240 VAC

24 VAC/VDC

Triac

120/230 VAC

Transistor MOSFET

24 VDC


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Relays

The most important consideration when selecting relays, or relayoutputs on a PLC, is the rated current and voltage.

For transistor outputs or higher density output cards relay terminalblocks are available.

Advantage of individual standard replaceable relays


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I/O Specifications

INPUT VOLTAGE Magnitude and type of voltage ON-STATE INPUT VOLTAGE RANGE voltage at which signal is

recognized

Nominal current per input Min. current to operate input circuit

AMBIENT TEMP RATING Max temp of surrounding the I/O

module INPUT DELAY Time duration for input signal to be on before

known as valid input. ( 9-ms to 25ms)

NOMINAL OUTPUT VOLTAGE It is min and max o/p operatingvoltage.e.g. Rated 120 v ac o/p ckt. Works in 92 to 138 v range.

MAX O/P CURRENT RATING Max current a single o/p ormodule can safely carry under load

OFF STATELEAK CURRENT PER O/P Max value of leak currentflows through the o/p in OFF position

ELECTRICAL ISOLATION Max volts between I/o and logic ckt.


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The power supply gives the voltage required for electronics module(I/O Logic signals, CPU, memory unit and peripheral devices) ofthe PLC from the line supply.

The power supply provides isolation necessary to protect the solidstate devices from most high voltage line spikes.

As I/O is expanded, some PLC may require additional powersupplies in order to maintain proper power levels.

P L C : Power Supply


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It is path for the transmission of the signal . Bus system is

responsible for the signal exchange between processor and I/Omodules

The bus system comprise of several single line ie wires / tracks

Types of Bus

P L C : Bus System

Address bus - Location

Data bus - Carries DataControl bus - Synchronization


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Special Modules

RF ID

Voice

Gas Flow Calculation

Weigh Cell

Hydraulic Servo

ASCII

Fuzzy Logic

Temperature Sensor

Temperature Control

Heat/Cool Control

Field Bus Cards

DeviceNet, Profibus etc

Lonworks, BACNet

Fast Response (Interrupt)

PID

Loop Controller

BASIC Cards

RS232 Comms Modbus ASCII/RTU

Ethernet Comms

High Speed Counters

Position Control Cards

Peer to Peer Comms Controller Link

DH+

Modbus Plus


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Input Scan

Program ScanOutput Scan

Housekeeping

START

Each ladder rung is scanned usingthe data in the Input file. Theresulting status (Logic beingsolved) is written to the Outputfile (OutputImage).

The status of external inputs(terminal block voltage) is written tothe Input image (Inputfile).

The Output Image data istransferred to the externaloutput circuits, turning the

output devices ON or OFF.

Internal checks onmemory, speed andoperation. Service anycommunication requests,etc.

PLC Operating Cycle

This scan cycle can be interrupted if required using interrupts


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PLC Architecture Evolution

Mid - 1970s : Discrete Machine Control

Programming

Terminal

PLC

I/O

Programming Language :

- Relay ladder logic- Flexibility in altering

Control system operation

Connection is Point to Point


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Early - to - Mid 1980 : Discrete and Process Control


Reasonable Computer

Running PLC

Programming Software

PLC

I/O

Programming Language :

- Ladder Program

- PID

- Data Storage

MS - DOS


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Late 1980s to early 1990s : Discrete and ProcessControl

PC runningPLC Programming Software

PLC

I/O

Connection in networked allowing

Multiple PLC

PLC became a part of the

developing enterprise resource

system

Windows

PLC


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Today: Distributed I/O Modules

Distributed I/O modules

PLC

Distributed I/O scanner

Data Communication Bus



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Remote

I/O Network

SPLITTERS

FIBER OPTIC LINK

TAPS

Today : Hot Redundant System


Level of redundancyPower Supply

CPU

I/OCommunication


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Controller Controller

Controller

Controller

Workstation Workstation Workstation Workstation

Switched Hub

PLC Architecture EvolutionToday : Ethernet Technology in PLCs


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Remote

Platform

Wireless Modem / GSM Communication

Wireless Modem / GSM Communication

PLC

H M I

Display

PC


Today : Wireless communication

PLC


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8 Analog Inputs 1Analog Output

Up/Down FastCounter

Up Counter

Programming Terminal PC Connection

Unitelway Port for connectionof up to 5 Slaves

PCMCIA memory expansion port

PCMCIA communications port

TSX37-22

Built in display for I/O(in-rack, AS-i) and Diag

I/O Modules

Configuration of PLC : Modicon


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Configuration of PLC : Siemens

CPU

External Power

Supply

I/O Modules


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Configuration of PLC : Allen Bradley

CPU

Power SupplyI/O Modules


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Configuration of PLC : GE FANUC

CPU

I/O Modules Back plane


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PLC Programming Standards

The open, manufacturer-independent programmingstandard for automation is IEC 61131-3. You can thus choosewhat configuration interface you wish to use when writing yourapplication :

Ladder Diagram

Statement List

Instruction List

Function Block Diagram

Sequential Function Chart

Structured Text


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PLC : Communication Protocol

It is a set of rules for data transmission when PLC is connected tonetwork

RS-232 (Recommended standard)

RS-485

MPI(Multi point Interface)

Profibus

DH(Data Highway)

Ethernet Controlnet

Devicenet


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Baud rate (Communication Speed)

It is rate of data transmission on network Unit is bits/second

Range:-120 bits /sec

to

100 Mega bits per second


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Selecting a PLC

Number of logical inputs and outputs

Memory

Number of special I/O modules

Expansion Capabilities

Scan Time

Communication

Software

Support

Cost


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Manufactures Major Brands

OMRON

Allen Bradley

Schneider

GE Fanuc Siemens

Automation Direct (Koyo)

Toshiba

Mitsubishi

Hitachi

Keyence

VIPA


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PLC Standardization

IEC 61131 Based on IEC 1131 (1992) standard, developed to be a

common and open framework for PLC architecture. IEC 61131-1 Overview IEC 61131-2 Requirements & Test Procedures IEC 61131-3 Data Types & Programming IEC 61131-4 User Guidelines IEC 61131-5 Communications IEC 61131-7 Fuzzy Control

IEC 61131-7 Guidelines for the application and implementationof programming languages


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PLC Programming

The purpose of a PLC Program is to control the state of PLCoutputs based on the current condition of PLC Inputs

Different PLCs support different languages, but the mostpopular PLC language is know as Ladder Logic.

PLC Ladder Logic purposely resembles Relay Logic


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| | |/|

Read / ConditionalInstructions Write / ControlInstructions

| | |/|

| | |/|

| |

| | |/| ( )

| |

( )

( )

( )

( )

| |

Start (Rung #1)

End (Rung #5)

Ladder Logic Concepts


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Read / Conditional

Instructions

Write / Control

Instructions

No Logical Continuity

|/| | |

True False False

|/| |/|

( )

( )

True True True

Logical Continuity

Ladder Logic Concepts


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IF input 4AND input 5have power

THEN energize output 0

| |I/4

| |I/5

( )O/0

Logical Continuity

T T T

On

Logical AND Construction


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|/|I/11

| |I/5

|/|I/7

|/|I/1

| |I/3

| |I/2

| |I/4

|/|I/0

| |I/1

| |I/1

|/|I/8

| |I/9

( )O/0

| |I/10

Typical Construction


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L1 L2

PB1 LS1 PS2 SOL6

DEVICE

PB1

LS1

PS2

SOL6

| | ( )| | | |I/5 I/6 O/0I/7

HHP

I/5

I/6

I/7

O/0

Logix

I:0/5

I:0/6

I:0/7

O:0/0

ADDRESS

Addressing Examples


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INPUT Address Assignment:

PB1- I/4 PB2- I/5LS1- I/6 LS2- I/7

LS3- I/8 LS4- I/9

OUTPUT Address Assignment:

SOL2- O/0 M1- O/1

|/|

CR3

CR3 M1

PB1 LS1 SOL2

PB2LS1

LS3

LS4

I/8

I/4 I/6 O/0

O/1

| | | | ( )

I/5I/7 B/0

| | | | ( )

| |

|/|B/0

( )

Relay Logic to Ladder Logic

| |I/9

l bl


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Available Instructions

Sequence Input

Output

Control

Logic

Timer and Counters Comparison

Range Comparison

Data Movement

Data Shift

Step / Step Next

Serial Communications

Text String Processing

File Manipulation

Increment/Decrement

Conversion

ASCII

Number Systems

Math

Floating Point Math

Statistics

Scaling

PID

PID with Auto tune

Clock / Date Block Processing

IF,THEN,ELSE,LOOP

Table Processing

LIFO, FIFO


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Few more Instructions

SEQUENCERS

SHIFT REGISTERS

DATA HANDLING

HIGH SPEED COUNTER

SUBROUTINES


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Programmable Logic ControllersSiemens

Si PLC


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Types of SIEMENS PLC:-

Compact:- I/O number fixed

Modular :- I/O can be as per selection

Siemens PLC


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SIMATIC S7-300 within the System Family

Mid- and low-endperformance range

S7-300

Micro PLCs

S7-200

+ Programming devices+ STEP 7 software

+ Communication

+ Human-machine Interface

High-end range /medium range

S7-400


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Highlights - Diverse applications

ET 200S, ET200X

Intelligent Interface modules,based on S7-300 or the standardS7-300 as PROFIBUS DP Slave

Distributed Safety -S7-300F with fail safe I/O modulesfor central and distributedapplications

C7 control systems

with integrated HMI on the basisof the S7-300

The C7 Systems are used where close integration with field, control and operation is required. For ex. Formulation andpackaging in Pharma industry. These are costly systems and are used only for some high end applications.

These are the remote I/O modules . Some of them have CPU inbuilt in them. The se I./Os are connected on Profibusnetwork.


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Siemens S7 Ranges

200 300 400

Series 212 to 226 312 to 318 412 to 418

Digital I/O 256 1024 16384

Analog I / O 38 256 4000

ProgrammingS/W Micro win Simatic Manager


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PS -Power Supply

CPU -Central Processing UnitIM -Interface ModuleSM -Signal Module(I/O modules)Bus Connector Rack (rail) Eleven slot railCP -Communication Processor

FM -Functional Module

Siemens S7 PLC Hardware


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The cost-effective entry into TIA The sophisticated solution for medium-range I/O configurations

CP The standard CPU for a wide range of applications with integratedPROFIBUS DP Interface

The new high-end CPU in S7-300

The high-performance CPU with system features of the S7-400

Siemens S7 300 CPU Overview


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The new standard CPUs

Instr. / DataUser memory

DI / DO

AI / AO

ProcessingtimeBit instructionWordinst. +/- IFloatingp.+/-R

Flags

Counters

Timers

Connections

Interfaces

315-2 DP

128 KB

1024

256

0,1 s1 s3 s

16384

256

25616

PROFIBUS-DP Master/Slave

CPU 317-2 DP

512 KB

1024

256

0,05 s0,2 s1,0 s

32768

512

51232

PROFIBUS-DP(Master/Slave)MPI also. DP

CPU 318-2 DP

84 K / 256 KB512 KB

1024

256

0,1 s0,1 s0,6 s

8192

512

51232

PROFIBUS-DP(Master/Slave)MPI also DP

CPU 314

48 KB

1024

256

0,1 s1 s3s

2048

256

25612

CPU 312

16 KB

256

64

0,2 s2 s6 s

1024

128

1286

Th C t CPU Hi hli ht


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The Compact CPUs - Highlights

Integrated functions

Count/measure, control, positioning

Integrated I/O

Digital, Analog

Integrated communication interfaces

In addition to MPI, also PROFIBUS DP and point-to-point

CPU 312CCPU 313CCPU 313C-2 PtPCPU 313C-2 DP

CPU 314C-2 PtPCPU 314C-2 DP

T t d di ti f ti


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Test and diagnostics functions

System diagnostics Fault diagnostics from CPU to I/O

internal CPU services (e.g. error message with time stamp)

Process diagnostics ( Seperate PDIAG software is required) Monitoring critical process signals at the program level

Simply assign parameters using S7-PDIAG and ProAgent

CPU generates messages automatically for S7 HMISo that your service personnel can diagnose the problem sooner

C C i i


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CPU Communication ports

MPI Profibus

Baud ratemax

1.5 Mb PS Default

187.5 KbPS12 Mb PS

No. of max.

nodes 32 126

NetworkLength

4000 Ftwithoutrepeater

4000 Ftwithoutrepeater

MPI is used for PLC programming, inter CPU communication, SCADA/HMI communication

In addition to above Profibus is also used for remote I/Os and Drives communication .Now a days Profibus is implemented on industrial Ethernet as Profinet.Profibus can also be implemented using fibre optic technology.

M d l f S7 300


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Modules for S7-300

Power Suppliesclassified according to capacity

Signal modules

for digital and analog signals and hazardousareas

Point-to-Point CPsfor I/O devices of all kinds

Function modulesfor high-speed counting, positioning, closed-loop control and cam control

Si S7 300 Di i l d l


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Siemens S7 300 - Digital modules

Voltage/current range

Channels(optically isolated)

Sensors

Resolution

Encoding time

Ex (i)

Diagnostics

Digital outputs

DC 24 / 48...125 VAC 5...230 V0,5 / 1 / 2 / 5 A

8, 16, 32electr./ Relay

Namur / Ex(i)

yes

Digital inputs

DC 24...125 VAC 120 / 230 V

8, 16, 32

Switches,2-wire Beros

Namur / Ex (i)

yes

Si S7 300 A l d l


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Voltage/current range

Channels(optically isolated)

Sensors

Resolution

Encoding time

Ex (i)

Diagnostics

Analog outputs

+/- 10 V, 0...10 V,+/- 20 mA,0/4...20mA, u.a.

2, 4, 8

12 - 16 bit incl.sign bit

0.8 ms

Namur / Ex(i)

yes

Analog inputs

+/- 80mV...10 V,+/-3,2mA,0/4...20mA u.a.

2, 4, 8with integratedlinearization

2-,3-,4-wire resistor(Pt100),thermocouples

9 to 16 bit incl.sign bit

2.5 ... 100 ms

Namur / Ex (i)

yes

Siemens S7 300 - Analog modules

Point to point CPs for special interfaces


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Point-to-point CPs - for special interfaces

1 or 2 interfaces, up to 76 kbit/s Different physical transmission

environment Standard or custom-specific

protocols

Programmingdevice, PC,computers

Robotcontrols

Opto-electronics

Printer

SIMATIC S5 and also PLCsfrom other manufacturers

Scanner,barcode reader,identificationsystems

Weighing systems,controllers

Siemens S7 300 Function Modules (FM)


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Siemens S7 300 - Function Modules (FM)

The FM are used when ... tasks have to be taken care of

at top speed ... The very highest accuracy and

reproducibility are required

... Special sensors or actuatorsare required

... technologicaltasks requirepracticalsolutions

Counting, measuring,cam control, positioning,closed-loop control

Siemens S 7 300 Design


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Siemens S 7 300 Design

Rugged, enclosedmodules

Integrated, easy-to-connectbackplane bus

High module density,

up to 32 channels per module Minimum mounting depthdue to recessed

and covered connectors and plugs

Power supply modules in the case ofAC mains connection for supplying theS7-300 and sensors/actuators

Siemens S7 300 Mounting


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Siemens S7 300 - Mounting

Simply snap the module onto the mounting rail

No slot rules

No jumper settings requiredon the module

Horizontal or vertical mounting

Front connectors with in

Screw- or

Spring-loaded terminals

Self-codingfront connectros

make sure that the rightconnector is plugged in aftermodule replacement

CPU M i ti


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CPU memory divided in blocks:-

OB -Organization Block(OB1-main block)FC -Functions(Subroutine user defined)FB Functional Block(defining function with memory)DB -Data Block(creating memory data)

SFC -System Functions (syst. Block)SFB -System Function block(syst. Block)

CPU Memory organisation



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Load memory:- User program stored, capacity can be

changed by MMC up to 256k

Work memory:-Instructions required program execution

System memory:-Holds OS, Timer, Counter, memory bits,

Process Image Memory, buffer diagnostics.


Siemens Addressing Concepts


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All the addresses are based on byte numbers.The Singnal Modules (I/O) can be put from slot no 4 onwards. When we do the I/Oconfiguration byte numbers required for each module are defined by the system which wecan use in the programming.

In certain CPUs these Byte numbers can be changed by the user. Generally system definedaddressing is preferred as it avoids memory holes.

Siemens Addressing Concepts

The typical addressing in Siemens S7 300 compact PLCs is as follows

Digital Input starts with I 124.0 (Byte No 124) ,

Digital Output starts with Q 124.0 (Byte No 124)

Analog Input starts with PIW 256 or PIW 752

Analog Output starts with PQW 256 or PQW 752

Similar I/O mapping is followed for Profibus Dp based remote I/Os

Siemens I/O Addressing


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I 0 . 0 (0 to 7)I 1 . 0 (0 to 7)Q 0 . 0 (0 to 7)Q 1 . 0 (0 to 7)

Four Bytes are allotted for each slot

32 I/O are permitted in each slot

One rail 8 slot are for SM,DP&FM

32 .8 =256 I/O in one rail

Four rail configuration permitted

256 . 4 = 1024 I/O permitted in four rails

Compact Module address is 124 to 127

INPUTorOUTPUT

BYTE

ADDRESS

BIT

ADDRESS

Siemens I/O Addressing

Siemens Memory addressing


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M-Marker memory

MB-memory byteMW-memory wordMD-memory double word

If total memory bits 1024 then 1024/8=128Memory byte no. - 0 to 127Bit Level Address:-M0.0M0.7M1.0M1.7..M127.7Byte Level Address:-MB0,MB1,MB2,MB3,MB1278 BITS=255 OR -128 TO 127


Siemens follows overlapping memory areas so user should be careful in usingthis addresses



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WORD Level Address:-MW0,MW2,MW4,..MW126

16 BITS = 65535 OR -32768 to 32767Word address is used to display Timer & counter value and for

Integer function within above limitDOUBLE WORD Level Address:-MD0,MD4,MD8,MD12432 BITS = -2147483648 to 2147483647

Double Word address is used for Integer function value morethan word limit




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TIMER :-T0 T 511(depends on module)COUNTER :- C0 C 255 FC :- FC1.. FC 511 FB :- FB1. FB 511 DB :- DB1. DB 511


Siemens Programming Language


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I0.0 I0.1 Q0.0Ladder :- ------||-----||-----------( )----

STL :- Structural Text LanguageA(A I0.0A I0.1)

= Q0.0




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FBD:- Functional Block Diagram

I0.0 Q0.0I0.1 & =


Siemens Syntaxes in programming


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I(Integer) - MW(word address)W(Word) - ,,

D (Double) - MD (double word address)DI (Double Integer) - ,,DW (Double Word) - ,,

R (Real) - ,,

Siemens Syntaxes in programming

Siemens Types of MPI adapters


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PLCMPI ADAPTER

PCRS485 RS232

PLCUSB ADAPTER PCRS485 USB

Universal Serial Bus

Siemens Types of MPI adapters

Siemens Organisational Blocks


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OB1 Main cuclic execution block. All other blocks must be called from here.

OB10 - 17 Time-of-day interrupts Execution to be done on specific time can be called here.

OB20 - 23 Time-Delay interrupts Keep repeating after delay time.

OB10 &35 Cyclic interrupts Keep repeating aftre defined time interval

OB40 - 47 Hardware interrupts Certain hardware moduels are capable of generatinginterrupts for ex. High speed counter. These blocks are executed when the hardware interrupts aretriggered.


These are interface between user program and operating system.



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OB60 Multicomputing interrupt Used when multi cpu systems are usedOB100 Warm restart - Memory retained but program starts from begining

OB 101 Cold Restart Initialise memory and start from begining

OB121, 122 Error interrupts When error happens it triggers these interrupts


Siemens S7 300 Central Configuration


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im361

IM361

IM361

IM360

Cable upto 10 meter

Siemens S7 300 Central Configuration

With the 312 and 312C CPUsonly a single structure ispossible on one rack

No restrictions to the selectionof modules

Central rack + max.3 expansionracks possible- 32 modules

Siemens Instructions


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----||----- NO----|\|---- NC----( )---- O/P COIL

----( S )---- SET COIL----( R )---- RESET COIL----( P)---- POSITIVE EDGE----( N )---- NEGATIVE EDGE

Siemens Instructions

Siemens LED Description


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SF 1. Hardware faults 2. Programming errors

3. Parameter assignment errors 4 Calculation errors

5. Faulty memory card 6. I/O fault/error

7. Communication error

BATF The backup battery is missing, faulty or not charged. It also is onwhen an accumulator is connected. The reason for this is that the user programis not back up by the accumulator.

STOP Flashes When CPU is not processing a user program.The CPU requests a memory reset




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5 V DC This must be ON. It shows CPU Logic power (5 V) available.

FRCE If any I/O force exist in CPU it will glow Yellow.

Run Solid green represents CPU in Run Mode

STOP Solid Yellow CPU in stop mode



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Programmable Logic ControllersAllen Bradley

PLC Ranges Available


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PICOMicroLogix

Compact LogixSLCPLC Obsolete (Control Logix is used)Flex Logix Discontinued

Control Logix

g

Allen Bradley PLC


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PLC S/W I/O capacity

Pico Pico soft 32

Mirco Logix RS logix500 156SLC 500 RSlogix500 4096/4096

Logix platform RSlogix5000 1,28,000

Communication s/w:-

RS linx :- With variety of software drivers

y

AB PLC Hardware


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Central Processing UnitInput ModuleOutput Module

Power supplyBus SystemRack (chassis)

Chassis types:-

4,7,10&13 Slots

(17 slots in Logix Platform)

AB PLC Hardware

AB PLC CPU Memory Organisation


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CPU memory divided in two parts:-Data Files

Program Files

Data files:-

System 0 -Manufacturer programSystem 1 -Reserve file

Ladder 2 -Main user file-ladder 3 to 255 for

subroutine program

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AB PLC CPU Memory Organisation


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Program files:-

0 -Output - O -- o/p status1 -Input - I -- i/p status2 -Status - S2 -- CPU data

3 -Binary - B3 -- Flag(memory bit)4 -Timer - T4 -- Timer status5 -Counter - C5 -- Counter status

6 -Control - R6 -- Specific data7 -Integer - N7 -- whole no. data8 -Float - F8 -- Decimal no.data

9 to 255 used to create new Program Files

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AB PLC Addressing I/O


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: . /

I : 1 . 0 / 0 (0 to 15)

I : 1 . 1 / 0 ,,O : 2 . 0 / 0 ,,O : 2 . 0 / 0 ,,

FILE

LETTERSLOT

NO

WORD

NO

BIT

NO

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Addressing BINARY (Flag)


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: /B3 : 0 / 0 (0 to 15)

B3 : 1 / 0 ,,. . .. . .. . .

B3 : 15 / 15

FileLetter

FileNumber

WordNumber

BITNumber

g g

Addressing of Programming Instructions


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TIMER :- T4:0 . T4:255(as per PLC)

COUNTER :- C5:0. C5:255CONTROL :- R6:0. R6:255INTEGER :- N7:0 N7:255

FLOAT :- F8:0. F8:255

g f g g

Addressing of Symbols


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----||----- XIC NO

----|\|---- XIO NC----( )---- OTE O/P COIL

----( L )---- OTL O/P COIL----( U )---- OTU O/P COIL

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Communication Protocols Comparison


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DH+ DH485 DeviceNet

ControlNet

Baud ratemax

230.4kbits/s

19.2kbit/s

500kbit/s

5 Mbit/s

No. ofmax.

nodes

64 32 64 99 1

NetworkLength

3.048 km 1.2 km 0.487 km 30 km 15 m

Communications protocols are broadly distinguished by speed of the communication,number of nodes supported and length of network.

p

AB_DF1

19.2 kbp/s


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Allen Bradley : SLC system

System Components


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y p

A modular-hardware SLC / 1746 control system at minimum consists of aprocessor module and I/O modules in a single 1746 chassis with a powersupply. The 1746 power supply connects to the left end of each 1746 chassis.You can configure a system with one, two, or three local chassis, for a total of30 local I/O or communication modules maximum. You connect multiple

local chassis together with chassis interconnect cables to extend thebackplane signal lines from one chassis to another.

Choose the processor module with the on-board communication ports youneed. You optionally add modules to provide additional communicationports for the processor. For I/O in locations remote from the processor, you

must add an I/O scanner module for ControlNet, DeviceNet, or UniversalRemote I/O port.

Product Design : CPU


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The 1746/1747 platform provides a modular-hardware system formaximum flexibility. SLC 500 processors are single-slot modules that youplace into the left-most slot of a 1746 I/O chassis. For 1746 I/O in alocation remote from the processor, the I/O adapter is a single-slot

module that you place into the left-most slot of a 1746 I/O chassis.

The 1746 I/O chassis are built for back-panel mounting and are available.

g

SLC 500 processors are available with4096 Input and 4096 OutputUser memory 1K instructions with 64K wordsLocal and Distributed I/O using I/O scanner module with Control / Devicenet or remote linkBuilt in 1 or 2 communication ports

Provision for expansion of memory



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You can configure a system with one, two, or three local chassis, for atotal of 30 local I/O or communication modules maximum. You connectmultiple local chassis together with chassis interconnect cables to extendthe backplane signal lines from one chassis to another.

For many modules, because you wire to a removable terminal block thatunplugs from the module, you do not need to disconnect wiring toreplace an I/O module.

g



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SLC 500 processors are available in a large range of forcible I/O (4096inputs plus 4096 outputs maximum) and maximum user memory (1Kinstructions through 64K words). Several modular processors are capableof controlling remotely located I/O. By adding an I/O scanner module,you can use these processors to monitor/control these remotely located

I/O across ControlNet, DeviceNet, and Universal Remote I/O links.

The 1746/1747 platform provides a modular-hardware system formaximum flexibility. SLC 500 processors are single-slot modules that youplace into the left-most slot of a 1746 I/O chassis. For 1746 I/O in alocation remote from the processor, the I/O adapter is a single-slotmodule that you place into the left-most slot of a 1746 I/O chassis.

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Product Design : Chassis and I/O


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The 1746 I/O chassis are built for back-panel mounting. The 1746 I/Ochassis is available in sizes of 4, 7, 10, or 13 module slots. The 1746 I/Omodules are available in densities of a maximum of 32 I/O per module.

You can configure a system with one, two, or three local chassis, for atotal of 30 local I/O or communication modules maximum. You connectmultiple local chassis together with chassis interconnect cables to extendthe backplane signal lines from one chassis to another. This same 30-I/O-module limit applies to a chassis remote from the processor with an I/Oadapter module in the first slot.

gmodules

Communication


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Various models of SLC processors have various on-board ports forcommunication with other processors or computers. Also, separatemodules are available to provide additional communication ports forcommunication with other processors, computers, and remotely located

I/O.

Each SLC processor has one or two built-in ports for either EtherNet/IP,DH+, DH-485, or RS-232 (DF1, ASCII, OR DH-485 protocol)communication.

I/O adapter modules for 1746 I/O are also available for ControlNet andUniversal Remote I/O links.

Communication Protocols


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Comparison

DH+ DH485 DeviceNet

ControlNet

Baud ratemax

230.4kbits/s

19.2 kbit/s 500 kbit/s 5 Mbit/s

No. of max.nodes

64 32 64 99

NetworkLength

3.048 km 1.2 km 0.487 km 30 km

Communications protocols are broadly distinguished by speed of the communication, number of nodes

supported and length of network.

PLC Programming Software


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Documents

P L C in industrail automation