Mitsubishi Electric RJ71C24-R4 MELSEC iQ-R Serial Communication Module

Description

Designed for seamless integration within the MELSEC iQ-R Series programmable controller platform, the RJ71C24-R4 serial communication module provides dual-channel RS-422/RS-485 serial interfaces. This module enables direct data transmission between the PLC system and peripheral devices such as human-machine interfaces (HMIs), frequency inverters, temperature controllers, and barcode readers. By supporting standard protocols including MC protocol, Modbus/RTU, and non-procedural communications, the RJ71C24-R4 facilitates highly reliable serial networking in industrial environments without requiring complex transmission programs.

Features

• Dual-channel configuration featuring two dedicated RS-422/RS-485 serial ports.
• Direct installation onto the MELSEC iQ-R series main base unit.
• Supports MC protocol, Modbus/RTU master/slave, and bidirectional non-procedural communication.
• Simplifies programming through pre-defined protocol support and dedicated PLC instructions.
• Provides robust diagnostics and monitoring capabilities through GX Works3 engineering software.

Applications

• Factory automation and control systems.
• SCADA and HMI monitoring network integration.
• Distributed peripheral device control (Inverters, Sensors, and Actuators).
• Legacy serial-to-PLC communication bridging.

Technical Specifications

Connections and Interfaces

Installation Guidelines

• Ensure the system base unit power supply is switched completely off before mounting or removing the module.
• Secure the module firmly onto the MELSEC iQ-R base unit using the module fixing hook and secure locking mechanism.
• Utilize shielded twisted-pair cables for all RS-422 and RS-485 connections to minimize electromagnetic interference (EMI).
• Connect terminating resistors (typically 110 or 330 ohms) across SDA/RDA or RXD+/RXD- terminals depending on the network configuration.