Overview

The ABB PM851 Controller Module is part of the AC 800M controller series, serving as the central processing unit in ABB’s System 800xA. It executes control logic, manages communication with I/O modules, and coordinates overall system functions.

The PM851 is a 32‑bit PLC controller equipped with a 1.2 GHz CPU, 1 GB RAM, and 128 MB flash memory, making it suitable for complex automation tasks. It is SIL 3 certified and IEC 61508 compliant, enabling use in safety-critical applications such as power generation, oil & gas, and chemical processing.

Technical Data

Typical Applications

• Power generation: Turbine and excitation control systems.

• Process industries: Chemical, oil & gas, and pharmaceutical plants requiring high‑availability control.

• Water treatment facilities: Supervises pumps, valves, and monitoring equipment.

• Manufacturing automation: Controls robotic systems, conveyors, and production lines.

• Safety‑critical systems: Certified for SIL 3 applications where fault tolerance is essential.

Example: In a refinery, the PM851 controller executes process logic, communicates with distributed I/O, and ensures safe operation even under demanding conditions.

FAQ

Q1: What is the ABB PM851 used for?
A1: It is a controller CPU module for ABB’s AC 800M and System 800xA platforms.

Q2: Does it support redundancy?
A2: Yes, but Ethernet redundancy is limited (only CN1 port available).

Q3: Is it suitable for safety applications?
A3: Yes, it is SIL 3 certified and IEC 61508 compliant, making it suitable for safety‑critical systems.

Q4: What communication interfaces are available?
A4: It includes Ethernet ports and RS‑232C serial ports, plus an isolated port for configuration.

Q5: Which ABB systems are compatible?
A5: It integrates with System 800xA, AC 800M controllers, and S800 I/O modules