Mitsubishi A68RD4 Digital I/O Module for MELSEC-F FX Series

The Mitsubishi A68RD4 (A68RD4) is a combined digital input and output module designed for use with Mitsubishi Electric MELSEC-F FX series programmable logic controllers. This discontinued unit provides a mixed I/O interface that integrates both input and output functions into a single compact device, functioning as an equivalent to the FX24MTDSS hardware specification. Engineered to expand system connectivity, the module features a total of 24 digital I/O points, configured as 12 digital inputs operating at 24 V DC alongside 12 digital outputs operating at 24 V DC with positive logic (source output). This combined configuration enables efficient signal acquisition from sensors, switches, and pushbuttons while simultaneously driving actuators, indicator lights, and small relay loads across industrial automation setups. By condensing 12 inputs and 12 outputs into a unified footprint, the module helps optimize panel space in control cabinets and simplifies wiring for machine automation, manufacturing lines, and process control applications that require coordinated digital signal monitoring and control within MELSEC-F system architectures.