Mitsubishi Electric A1SJHCPU-S8 Programmable Logic Controller CPU Module

The Mitsubishi Electric A1SJHCPU‑S8 is a MELSEC‑A series programmable logic controller (PLC) CPU module that provides on‑board logic execution and I/O coordination for industrial automation projects. As the central processing unit in Mitsubishi’s MELSEC‑A racks, it handles control logic, sequencing, interlocks, and timing for sensors, actuators, and discrete or expansion I/O modules. It includes on‑board program memory for user programs and data, supports backplane bus communication, and offers optional serial or Ethernet adapters for networked control. LEDs indicate power, run, error, and status to aid maintenance and diagnostics; it mounts in a PLC rack slot and is powered through the backplane. Designed for industrial temperature ranges, it is intended for logic execution, I/O coordination, and machine control across factory and process automation environments, including conveyors, packaging machinery, material handling equipment, assembly lines, machine tools, and standalone automated systems requiring sequencing, interlocking, and timing. Common replacements include A1SJHCPU‑S6 and A1SJHCPU‑S12, with Omron CJ1M‑CPU13 listed as an alternate PLC CPU.