Yokogawa ALR111 Communication Modules

Yokogawa ALR111 General

This document describes about Models ALR111 and ALR121 Serial Communication Modules used with a safety

control station (SCS) for performing Modbus communication.

By using the SCS’s Modbus slave communication function, the data in SCS can be set or referred to by the Modbus master which is as separate system from SCS via a serial communication module.

Furthermore, the subsystem data such as from sequencers can be set or referred to via a serial communication module using SCS’s subsystemcommunication function.

These serial communication modules can be mounted on SSC60, SSC50, and SSC10 safety control units and SNB10D safety node unit that are connected with safety control units by ESB bus.

ALR111 Operating Environment

Hardware Requirements

The serial communication module runs on the following SCS.

SSC60S, SSC60D, SSC50S, SSC50D, SSC10S, SSC10D



Software Requirements

The serial communication module runs on the control functions on the following SCS.

CFS1300 Safety Control Functions Package (for SSC60 and Vnet/IP): for SSC60

CFS1100 Safety Control Functions Package: for SSC50/SSC10

Engineering Requirements

Engineering work can be performed with CHS5100 Safety System Generation and Maintenance Function Package

ALR111 Modbus Communication

Connected device: Serial transmission interface module

Connection method: Connect an ALR111 or ALR121 module communication port with serial transmission interfacemodule

Applicable devices: By Yokogawa - STARDOM FCN, FCJ, and GC1000 Mark II (*1)

By Schneider Electric - Modicon484, 584, 584L, 884, 984, 984A, 984B, 984X, and Micro 84

By Yasukawa Electric - Memocon-SC U84, 584, 684H, 694H, R84H-M, GL60S, and GL20

Transmission protocol: Modbus protocol (RTU mode)

ALR111 MELSEC-A Communication

Connected device: MELSEC-A computer link unit

AJ71C24-S8/S6/S3, AJ71UC24, A1SJ71UC24-R2/R4/PRF, A1SJ71C24-R2/R4/PRF,

A1SCPUC24-R2, A2CCPUC24 (PRF)

Connection method: Connect a computer link unit with ALR111 or ALR121 communication ports

Applicable devices: MELSEC-A CPU unit

(A communication with FCS can be established with if a CPU is connectable with MELSEC-A

computer link unit.)

Transmission protocol: MELSEC-A dedicated control protocol format 4

No. of subsystem stations: Max. 30 stations/port

DUAL-REDUNDANCY OF COMMINUCATION

ALR111 Functional Overview

When the communication function complies, the dual-redundant configuration (*1) can be provided by setting the serial communication modules to dual-redundant.

Each of the ALR111 and ALR121 modules has two ports; however, the dual-redundant communication requires two communication modules.

The two sets of dual-redundant communication are enabled by two ports of ALR111/ALR121; however, the communication control is defined by each communication module. When one of the communication ports detects an

error, both ports switch over the control/stand-by sides to the redundant module.

Note that the one-shot write specification cannot be used when dual-redundant communication is set.

*1: Refer to “Table Communication Functions Communication Modules.”

Data Input Flow

Each of the two ALR111/ALR121 modules communicates with the subsystem and reads the subsystem input image data into the module.

An FCS accesses the control communication module to read and use these data; however, it does not access the standby communication module.

When the FCS detects a control communication module error or subsystem communication failure, the FCS switches its control to the standby module from which to read data.

Data Output Flow

A control communication module outputs data to a subsystem. The control communication module writes data to the subsystem at the specified intervals when an FCS sets the data in it.

Meanwhile, the standby communication module re-reads and retains the output image data when it accesses the subsystem at the specified interval.

This equalizes the data between the control and standby communication modules.

When an error is detected, the FCS switches its control to the stand-by module through which the FCS continues to output data to the subsystem.

Recommend Modules