PM856K01 is a compact processor unit for ABB AC800M control platform under System 800xA architecture. Compliant with IEC61131‑3 standard, it supports multiple programming languages to implement process regulation, sequence logic and analog closed‑loop control. On‑board RAM and Flash satisfy medium‑scale application program storage and real‑time data processing requirements.This is a non‑redundant CPU unit designed for standard automation projects. Rich communication interfaces connect S800 I/O modules, fieldbus instruments and upper monitoring host. Built‑in lithium battery protects programs and runtime data against unexpected power loss. Rugged hardware with good EMC performance ensures stable running in regular plant‑site environments.Typical applications cover light chemical, water treatment, municipal industry and general manufacturing automation. Back up application program before module replacement and confirm firmware compatibility. Complete configuration download after installation. Fully cut off power supply during hardware maintenance. Suitable for on‑site fault replacement and long‑term spare stocking of running System800xA / AC800M systems.