ABB PM858K01/02 High-Performance Controller | AC 800M Redundant CPU

ABB PM858 is a high-performance controller unit within the ABB AC 800M series, designed for advanced industrial automation and process control systems. As a core component of the ABB Ability™ System 800xA, the PM858 delivers powerful processing capabilities, extensive communication options, and support for CPU redundancy to ensure maximum system availability in critical applications.

This controller is ideal for industries requiring high reliability and safety, including oil & gas, petrochemical, power generation, pharmaceuticals, and water treatment. Its robust design, comprehensive certifications, and flexible configuration options make it a preferred choice for demanding distributed control systems (DCS).

Key Features

CPU Redundancy Support: The PM858 can be configured as a single (PM858K01) or redundant (PM858K02) processor unit, providing seamless switchover with max 10 ms failover time to prevent downtime.

High Processing Performance: Powered by a 33 MHz MPC866 processor with 16 MB RAM and 4 MB Flash PROM, capable of handling complex control tasks and multiple communication protocols.

Extensive Communication Interfaces: Equipped with 2 Ethernet ports (10 Mbit/s) for control network connectivity (MMS/IAC protocols) and 2 RS-232C serial ports (COM3 for general use, COM4 isolated for configuration).

Safety & Reliability: TÜV certified and compliant with IEC 61508-SIL3, suitable for safety-critical applications when combined with SM812 module and SIL-certified software.

Industrial Grade: Operates in temperatures from +5 to +55 °C, features built-in battery-backed real-time clock, power reserve for controlled shutdown, and LED status indicators for diagnostics.

Modular Design: DIN rail mounting, detachable power connector, and support for up to 12 communication modules on the CEX bus, with Modulebus supporting up to 96 I/O modules.

Technical Specifications

Parameter Details

Product Type Controller CPU Module

Series ABB AC 800M / System 800xA

Processor MPC866, 33 MHz

Memory (RAM) 16 MB (7.147 MB available for application from 5.1 FP4)

Flash Memory 4 MB for firmware and application storage

Ethernet Ports 2x RJ45 (10 Mbit/s, IEEE 802.3)

Serial Ports 2x RJ45 (COM3: RS-232C, COM4: Isolated RS-232C)

CEX Bus Support Up to 12 communication modules

Modulebus I/O Capacity Up to 96 I/O modules (non-redundant), up to 84 I/O modules (redundant)

Redundancy Support Yes (CPU, CEX-Bus, Communication interfaces, S800 I/O)

Switchover Time Max 10 ms (redundant configuration)

Power Supply 24 V DC (19.2 – 30 V DC)

Typical Power Consumption 5.1 W

Operating Temperature +5 °C to +55 °C (+41 °F to +131 °F)

Storage Temperature -40 °C to +70 °C (-40 °F to +158 °F)

Protection Class IP20

Safety Certification IEC 61508-SIL3, TÜV (with appropriate configuration)

Dimensions (H x W x D) 119 mm x 186 mm x 135 mm

Weight Approx. 2.7 kg (including baseplate)

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Product List & Ordering Information

The PM858 controller is typically ordered as a complete kit (Processor Unit) rather than a standalone CPU. Below are the primary product codes:

Order Code ABB Part Number Description Included Components

PM858K01 3BSE082895R1 Single Processor Unit (Non-redundant) 1x PM858 CPU, 1x TP830 Baseplate, 1x TB807 ModuleBus terminator, 1x Battery

PM858K02 3BSE082896R1 Redundant Processor Unit (High Availability) 2x PM858 CPUs, 2x TP830 Baseplates, 2x TB807 terminators, 1x TK850 CEX-bus cable, 1x TK851 RCU-Link cable, 2x Batteries

PM858 (CPU only) 3BSE093350R1 Standalone CPU Module (without baseplate/accessories) 1x PM858 CPU module

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Required Accessories & Related Modules

To build a complete control solution, the following components are commonly ordered alongside PM858K01/02:

Category Model / Order Code Description

Baseplate TP830 Required baseplate for mounting the PM858 CPU, provides backplane connectivity

CEX-Bus Terminator TP850 Required to terminate the CEX-Bus expansion bus

ModuleBus Terminator TB807 Required for ModuleBus termination

External Battery Unit SB822 Optional external battery for extended RAM backup time

Redundancy Cable TK851 RCU-Link cable for connecting two CPUs in redundant configuration

Communication Modules CI853, CI854, CI857, CI858, CI867, CI871, etc. PROFIBUS, Modbus, Ethernet/IP, and other protocol interfaces

Power Supply SD831, SD832, SD833, SD853, SD854 24 V DC power supply units for the controller and I/O system

Applications

The ABB PM858 controller is widely used in:

Process Control Systems (DCS): For precise and stable control of reactors, distillation columns, boilers, and turbines in oil & gas, chemical, and power plants.

High Availability & Critical Processes: Redundant configuration (PM858K02) ensures continuous operation in emergency shutdown systems (ESD), burner management, and critical utilities.

Manufacturing Automation: Control of large machinery in mining, metals, cement, and pulp & paper industries, including mills, crushers, kilns, and conveyors.

Infrastructure: Water and wastewater treatment plants, HVAC systems, and building automation where reliability and remote monitoring are essential.