slc 500 communications

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SLC 500 Communications

SLC 500

COMMUNICATIONS

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SLC 500 CommunicationsRequirements for

Industrial Networks

An industrial communication link Capable of supporting real-time control High data integrity High noise immunity High reliability in harsh environments Suitable for large installations

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Local Area Network - Applications

Centralized Data Monitering and Acquisition Manufacturing SCADA MMI

Distributed Control Communication between programmable controllers Upload to a programmer or host computer from any PLC Download from a programmer or host computer to any PLC Read/write I/O values, registers of any PLC Monitoring of PLC status and control of PLC operation

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Network Topologies

Daisy-Chain– Each device has two sections of cable tied together– Each end has termination (resistor/capacitor)

SLC SLC SLC SLC

ExamplesDH+DH-485Remote I/O Beldon #9463 cable

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Network Topologies

Star– All devices physically connected at one point

PLC PLC PLC

PLC

ExampleEthernet

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Network Topologies

Trunk-Line / Drop-Line– Trunk line very long - run through plant– Drop lines very short– Drops connected to trunk with Y-adapters

SLC SLC SLC SLC

Trunk Line

Drop Line Drop Line Drop Line Drop Line

ExamplesData Highway (DH)DevicenetDH+ can be

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Token Passing:– Each node can talk on the network when it

has the token– After done talking, the node will “Pass the

token” to the next node– Multi-master network– Eliminates data collisions

TOKEN

Network Access Methods

SLC SLC SLC SLC

# 1 # 2 # 3 # 4

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NetworkController(Master)

Request ?

Reply !

Network Access Methods

Master / Slave:– Master talks to one slave at a time– The slave can only talk if the master

asks it for some information– Polling network– Eliminates data collision– Single master network

SLC(Slave)

SLC(Slave)

SLC(Slave)

SLC(Slave)

# 1 # 2 # 3 # 4

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Maximum number of devices– How many nodes are required for the application?– How many nodes should be reserved for future

expansion?

Maximum network length– Usually specified as the physical cable distance from the

first node to the last node on the network– Drop length is the length of cable from the main cable to

the node

Device supported– Programmable controllers– Programming devices– Operator Interfaces– Other Computers - PCs, Workstations, Minis, Mainframes...

Response time Application interface

Networks - How to Decide on One?

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A-B Communication Network Terms

RS-232

RS-485

DH-485

REMOTE I/O

DF1

DH+

RS-422What the hell doall these mean?

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A-B Communication Network Terms

RS-232

RS-485

DH-485

REMOTE I/O

DF1

DH+

RS-422 }

}Electrical Connections

Protocols (languages)

Must have matching electrical connections and protocols for two computers to communicate.

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Communications - Like a Phone Call...

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Electrical Connection is made when person answers phone

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ENGLISH FRENCHCOMMS

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Communication when connection make AND both people speak the same language

ENGLISH FRENCH

ENGLISH ENGLISH

COMMS

COMMS

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Networks: DH-485 and DH+

Network Communications

– Program support and monitering

– Supervisory control for distributed hierarchy

– Operator interface for monitoring and control

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DH-485 Characteristics

DH-485 Multi-drop link

Daisy chain configuration

Token passing system

9.6 or 19.2 Kbaud data rate

Connect up to 32 devices on network

Up to 4000 cable feet (1200 meters) of network lenght

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DH485 Peer-to-peer Comms.

Send/Recv messages from other SLC 500s

Multi-master token-passing ring; 32 nodes

5/02, 5/03 + 5/04 can initiate communications to other processors

5/03 can using Channel 0, Channel 1, or both

5/04 can using Channel 0 only

Fixed and 5/01 respond only

Initiate comms. with MESSAGE instruction in ladder logic

NO ladder programming necessary to respond to a message from another processor

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Typical DH-485 Network

Link Coupler Link Coupler Link CouplerLink Coupler

SLC 5/03 SLC 5/02 SLC 5/01 SLC 500 Fixed

PIC

ALLEN-BRADLEY DTAM Plus

RUN ALARM

AIC+

SLC 5/04

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DH+ Characteristics

• Peer-to-Peer Communication– Utilizes Tolken Passing

• 64 nodes maximum• Remote Programming of SLC 500’S, PLC-2, PLC-

3, and PLC-5• Direct Connections to 5/04,PLC-5, Panelview, and

Industrial Terminals• 57.6, 115.2, OR 230Kbaud data rate• Pub # 1770-6.5.16 DH/DH-485/DH+ Ref Manual• Robust Industrial Network

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DH+ Communications

RSLogix 500 SoftwareAI 500 Software6200/AI Software

PLC-5

DH+

SLC-5/04 PLC-2, PLC-3PLC-5/250

OtherProcessors

57.6Kbaud: 10,000 feet115.2Kbaud: 5,000 feet230.4Kbaud: 2,500 feet

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DH+ to DH-485 Interface

Interface through a 1785-KA5– Translate DH-485 <-> DH+– Allows PLC5s and SLCs to communicate

RSLogix 500Software

Link Coupler

SLC 5/01

Link Coupler

SLC 5/03

Link Coupler

SLC 5/02

PLC-5 PLC-5

DH-485 Network #1 DH-485 Network #2

DH+

Link Coupler

SLC 5/03

SLC 5/04

DH+


RS-232 Communications

SLC-5/03 and 5/04 Support:

Full-Duplex (Point-to-Point)

Half- Duplex

ASCII

Modem Communication


RS-232: DF1 Full-Duplex

AKA: DF1 Point-to-Point

Simultaneous transmission between two devices in both directions

- Programming Port- Peer Messaging


RS-232: DF1 Half-Duplex

Mulit-Drop, Single Master, Multiple Slave

Slaves are Polled for Response from the Master

Supports up to 255 Slave Devices

Slaves: Any SLC Processor

Master: PLC-5, SLC-5/03, 5/04, CV

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5/03 + 5/04 Serial Port

Point-to-point communications

RS-232

Using Channel 0 w/ DF1 Full-Duplex

RSLogix 500Programming Software

Modem Modem

SLC 5/03 or 5/04

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5/03 + 5/04 Serial Port

Master/Slave communications

Polled Network

Using Channel 0 w/ DF1 Half-duplex Master or Slave

ModemModem

RSLogix 500 Programming Software

Modem

DF1 Master (RSView)

Modem

Master

Slave(s)

SLC 5/04SLC 5/03

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ASCII Communications

5/03 and 5/04

Direct connection to devices such as barcode decoders and printers

Eliminates requirement of BASIC module for this task

PROG

SLC 5/03 CPURUN

FLT

BATT

FORCE

RS232

DH485

RUN REM

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1747-KE Module

RS-232

RS-485

DF1

DH-485

Converts electrical signals– RS-485 to RS-232

Translates protocols– DH-485 to DF1

Configured thru the backplane (Series B)

RS-232 Config

DH-485 / RS-232

ACTBA LOW485

CFGDF1

FAULT

H/DF/D

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1747-KE Module

RS-485/DH-485 to RS-232C/DF1 interface module

Acts as a BRIDGE between two different networks or types of communication

Called a Bridge module

(1) DH-485 port

(2) Serial ports (RS-232, 422, 485)

Allows remote communications to SLC 500 systems

DH-485 / RS-232

ACTBA LOW485

CFGDF1

FAULT

H/DF/D

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Typical KE Configurations

Modem

Modem

RSLogix 500

Isolated Link Coupler 1747-AIC

SLC 5/01

SLC 500

DH-485

• Point-to-Point configuration using full duplex DF1 communications

• Remote communications from the programming software to a remote network of SLC 500 processors.

• RSLogix 500 acts as if it were directly on the DH-485 network

SLC 500 CPU with KE module

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Typical KE Configurations

SLC 500with KE

ModemModem

RSLogix 500 ProgrammingSoftware

Modem

DF1 Master (RSView)

Modem

Master

Slave(s)

SLC 5/01with KE

SLC 5/02with KE

Modem

Master/Slave communications

Polled Network

Using Channel 0 w/ DF1 Half-duplex Slave

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Read/Write: Read - local processor is receiving data Write - local processor is sending data

Target Device: 500CPU if target is another SLC Processor 485CIF if target is a non-SLC device on the network PLC5 if target device accepts PLC-5 commands

Local/Remote: Local - the message is to be communicated via a local network Remote - the message is to be communicated to a remote

device on another network through a bridge

Control Block: Contains - target node address, local file address, target file address, status bits

Control Block Length: Fixed at 14 elements

Setup Screen: Advanced setup parameters

EN: enable bit - set when rung is trueDN: done bit - message successfully transmittedER: error bit - transmission failed

Peer-to-Peer Communications

Setup Screen

Read/Write Message

Read/Write ReadTarget Device 500CPU

Control Block ? Control Block Length 14

MSG( EN )

( DN )

( ER )

Local/Remote Local

Type Peer-To-Peer

slc 500 communications

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