Mitsubishi RJ71EIP91 EtherNet/IP Communication Module

The Mitsubishi RJ71EIP91 is a dedicated communication module for the iQ-R series programmable logic controllers. It adds EtherNet/IP (Common Industrial Protocol) connectivity, allowing the Mitsubishi PLC to act as a scanner (master) or adapter (slave) on an EtherNet/IP network, facilitating data exchange with Allen‑Bradley CompactLogix/ControlLogix, drives, HMIs, and other CIP-enabled devices.

Technical Specifications

• Network standard: IEEE 802.3u (100BASE-TX) and IEEE 802.3 (10BASE-T)

• Transmission speed: 100 Mbps / 10 Mbps auto-negotiation

• Number of ports: 1 (RJ45, auto MDI/MDI-X)

• Supported functions: Explicit messaging, Implicit (I/O) messaging, UCMM, Class 1/3 connections

• Max connections: 32 (scanner) / 16 (adapter)

• Max I/O data size: 2048 bytes input + 2048 bytes output (scanner)

EtherNet/IP Features

The RJ71EIP71 supports the full EtherNet/IP specification including multicast filtering, RPI (Requested Packet Interval) down to 1 ms, and support for CIP Sync (time synchronization) and CIP Motion (limited). It can discover devices via EDS files and uses the standard Ethernet/IP object model.

Configuration and Programming

Configuration is performed using GX Works3 software. The module is added to the iQ-R rack configuration, and EtherNet/IP scanner settings are defined via a dedicated configuration tool within GX Works3. Users can assign tag names to CIP data and map them to global PLC labels. The module supports automatic device discovery and EDS file import.

Diagnostics and Monitoring

The module provides extensive diagnostic functions including connection status per device, communication error logs, packet statistics, and a built-in web server for remote monitoring (via HTTP). LED indicators: RUN, ERROR, LINK, and ACT. The module also supports CIP diagnostics via explicit messages.

Electrical and Mechanical Data

Power supply: 5V DC from backplane (0.3 A typical). Dimensions: 28mm width x 106mm height x 110mm depth. Weight: 0.2 kg. Mounting: iQ-R series base rack (R35B, R38B, etc.). Operating temperature: 0-55°C. Humidity: 10-90% non-condensing.

Isolation and Protection

The Ethernet port is isolated from the internal logic by 1500 Vrms. The module includes surge protection on the Ethernet interface (IEC 61000-4-5, 1 kV).

Certifications

CE, UL, cUL, EAC, KC, and RCM certified. The module is compliant with ODVA EtherNet/IP conformance test (optional validation). RoHS compliant.

Typical Applications

The RJ71EIP91 is used in mixed-vendor automation lines where Mitsubishi PLCs need to exchange data with Rockwell Automation controllers, or to control Allen‑Bradley PowerFlex drives, E300 overload relays, and other CIP devices. It is also suitable for connecting to vision systems and robot controllers.

Firmware Updates

Firmware can be updated via the Ethernet port using Mitsubishi’s firmware update tool. The module supports online firmware upgrade without stopping the PLC scan.

Conclusion

The Mitsubishi RJ71EIP91 EtherNet/IP module bridges iQ-R PLCs to the widespread EtherNet/IP ecosystem, providing high-speed, deterministic communication for integrated manufacturing systems.