Mitsubishi AJ71E71N-B5T Ethernet Communication Module
The Mitsubishi AJ71E71N-B5T is an intelligent communication module designed for the MELSEC AnS series programmable controllers. It provides an Ethernet interface (10BASE-T / 100BASE-TX) allowing the PLC to communicate with host computers, HMIs, and other network devices using TCP/IP, UDP/IP, or Mitsubishi’s dedicated MELSEC protocol.
Hardware Specifications
The module occupies one slot in an AnS base unit. It features a single RJ45 connector with auto-negotiation (10/100 Mbps). The internal processor is a 32-bit RISC (50 MHz) with 256 KB of buffer memory for send/receive frames. Power consumption: 5 V DC, 0.6 A from backplane. Dimensions: 98 mm x 27.4 mm x 115 mm. Weight: 0.2 kg. Status LEDs: module ready (green), link/activity (green/yellow), and error (red).
Supported Protocols
The AJ71E71N-B5T supports the following communication profiles: MELSEC communication protocol (active/passive), MC protocol (MELSEC Communication Protocol) for access to device memory from external devices, TCP/IP socket interface (up to 8 simultaneous connections), UDP broadcast/multicast, and FTP (file transfer for program/data files). It also supports SMTP for email alerts and time synchronization via SNTP.
Configuration and Programming
Parameter settings (IP address, subnet mask, port numbers) are stored in the module’s EEPROM and configured using GX Developer or GX Works2 (via PLC parameter tab). The module supports up to 16 KB of shared memory for cyclic data exchange with the PLC CPU. The user program in the CPU uses dedicated instructions (e.g., BUFRCV, BUFSND, OPEN, CLOSE) to manage socket connections. A sample library for C# or VB.NET is available for host application development.
Environmental and Compliance
Operating temperature: 0°C to 55°C. Storage: -20°C to 75°C. Humidity: 10% to 90% non-condensing. Vibration: 2 g (10-57 Hz). The module meets CE marking and RoHS. It is designed for installation in IP20 control cabinets.
Applications
Typical uses include remote monitoring of PLC data via Ethernet network, data logging to a central server, and interfacing with barcode scanners or weigh scales over TCP. The module is also used to connect multiple AnS PLCs in a simple LAN without requiring a gateway. For legacy systems, the AJ71E71N-B5T provides a modern Ethernet upgrade.
