ABB PM858K01 3BSE082895R1 AC 800M Processor Unit

The ABB PM858K01 3BSE082895R1 serves as the primary PM858K01 Processor Unit utilized to execute deterministic logic and control network communications across ABB System 800xA platforms. Powered by an MPC866 processor running at 33 MHz with 16 MB of onboard memory, this hardware unit processes field signals while managing communication traffic across local ModuleBus and CEX-Bus expansion interfaces. The module integrates dual RJ-45 Ethernet interfaces for control network access alongside two dedicated RS-232C serial communication ports.

Suffix Breakdown & Model Matrix

Hardware Specifications

Backplane Bus Communication Velocity & I/O Density Scaling

The CPU backplane interface manages deterministic scan cycles across local and expansion backplane buses, preserving signal integrity when scaling system I/O capacity. The internal ModuleBus architecture handles real-time updates for up to 96 S800 I/O modules with selectable scan rates between 0 and 100 ms. For external network expansion, the dedicated CEX-Bus backplane drives up to 12 communication interface units while delivering a maximum supply current of 2.4 A, sustaining fixed backplane bus communication velocity across high-density I/O configurations.

Frequently Asked Questions

Q: What is the current draw and backplane power capacity for attached CEX-Bus modules?

A: The processor unit operates on a nominal supply voltage of 24 VDC (19.2-30 VDC range), drawing 210 mA under typical load and up to 360 mA maximum. The internal power supply stage delivers up to 2.4 A of total current capacity to power attached CEX-Bus expansion modules.

Q: Can the PM858K01 processor unit be configured for hardware redundancy or high-integrity SIL applications?

A: No. The PM858K01 hardware structure is designed specifically as a single, non-redundant, non-high-integrity controller. It lacks redundant CPU cross-link synchronization hardware and must not be used in SIL3 safety loops.

Field Installation Guidelines

Mount the TP830 baseplate vertically on a standard 35 mm DIN rail inside a protective enclosure, maintaining at least 50 mm of vertical airflow space above and below the assembly. Ensure the TB807 ModuleBus terminator, TB850 CEX-Bus terminator, and TB852 RCU-Link terminator are firmly seated into their respective open bus ports to prevent high-frequency signal reflections. Connect the primary 24 VDC power supply using shielded cables, attaching the shield drain directly to the local functional ground terminal. When replacing the lithium backup battery (4943013-6), install the unit while system power is active to prevent loss of volatile application program memory stored in RAM.