Yokogawa ALR121-S53 Serial Communication Module DCS Interface

Product Description

Overview

The ALR121-S53 is a high-reliability serial communication module designed for Yokogawa CENTUM VP and CENTUM CS 3000 distributed control systems. This module provides seamless integration for RS-422/RS-485 serial devices, enabling efficient data exchange between the DCS and third-party subsystems. Typical connected equipment includes PLCs, analyzers, flow meters, motor control centers, and temperature controllers.

Key Features

• Dual independent serial ports for simultaneous communication with multiple devices

• Supports RS-422 (4-wire) and RS-485 (2-wire) signaling with individual port isolation

• Compatible with Modbus RTU protocol in master mode for flexible device interfacing

• Hot-swappable capability and dual-redundancy support for uninterrupted operation

• Front-panel LEDs indicate Run, Error, and Send/Receive status for rapid troubleshooting

Technical Specifications

Applications

• Industrial process monitoring via third-party analyzers and flow meters

• Data acquisition from PLCs and motor control centers

• Integration of subsystem sequencers and temperature controllers

• Safety control station communication using SCS Modbus slave function

FAQ

Q: Can the ALR121-S53 operate with different baud rates on each port?
A: Yes, each port can be configured independently to communicate at different speeds with different devices.

Q: Is the module compatible with hot-swapping?
A: The module supports hot-swapping, provided the base unit allows power-on replacement.

Q: Can I map external device registers directly to the DCS?
A: Yes, the module allows flexible mapping of external registers into internal DCS data points.

Q: Which safety control units are compatible with this module?
A: Compatible with SSC60, SSC50, SSC57, SSC10 series safety control units and SNB10D safety node units.