ABB PM866 3BSE050200R1 AC 800M CPU Module

The ABB PM866 3BSE050200R1, also cataloged as the PM866 CPU Module, operates as a dedicated hardware component for control logic execution and real-time process data processing within ABB System 800xA platforms. Built around an MPC866 processor running at 133 MHz with 64 MB of RAM, the module executes instructions at 0.09 ms per 1,000 Boolean operations. The unit provides hardware support for CPU redundancy, CEX-Bus expansion communication modules, and dual RJ-45 Control Network interfaces.

Hardware Specifications

Backplane Bus Communication Velocity & I/O Density Scaling

The internal backplane bus interface handles high-volume memory synchronization and field I/O data routing between the CPU core and connected hardware expansion racks. Operating with a ModuleBus scan rate from 0 to 100 ms, the processor maintains deterministic loop update cycles across high-density I/O configurations. In single CPU installations, the backplane drives up to 96 S800 I/O modules, while redundant CPU deployments maintain deterministic scan cycles across up to 84 I/O modules. The CEX-Bus backplane interface delivers up to 2.4 A of bus current to maintain communication velocity across up to 12 attached protocol modules.

Frequently Asked Questions

Q: How does CPU redundancy affect ModuleBus I/O module capacity and switchover performance?

A: In redundant processor configurations, the maximum supported ModuleBus capacity decreases from 96 to 84 I/O modules to maintain deterministic scan timing. Upon detection of a primary CPU hardware fault, the backup processor assumes control with a maximum switchover time of 10 ms.

Q: What are the current draw and power supply parameters for the PM866 unit?

A: The module requires a nominal 24 VDC power source with an allowable operating range of 19.2 to 30 VDC. Typical current consumption is 210 mA at 24 VDC (5.1 W dissipation), peaking at 360 mA at 24 VDC (8.6 W dissipation) under maximum backplane bus processing loads.

Field Installation Guidelines

Mount the processor baseplate vertically on a standard 35 mm DIN rail inside an IP54 or higher protective enclosure, providing at least 50 mm of vertical airflow space above and below the housing. Connect the 24 VDC supply lines using shielded wiring and ground the shield drain directly to the central functional earth terminal bar. Verify that bus terminators are installed firmly on open CEX-Bus and ModuleBus end ports to prevent signal attenuation and backplane communication errors. Observe ESD protection guidelines when inserting optional CompactFlash cards into the front memory slot while power is applied.