PM851AK01 ABB AC 800M CPU Processor Module Automation Unit

ABB PM851AK01 AC 800M Processor Module

Configured for high-speed logic execution within the System 800xA network, the ABB PM851AK01 (PM851AK01 CPU Module) provides direct electrical execution of control algorithms and I/O data processing for AC 800M controller platforms.

Hardware Specifications

Industrial Control and Network Determinism

The PM851AK01 manages backplane bus communication velocity to ensure synchronized data exchange across the AC 800M distributed I/O network. This processor supports I/O density scaling, allowing for the addition of various communication and signal conditioning modules within a single rack configuration. Its architecture maintains firmware flash compatibility, permitting updates to internal logic and communication stacks without hardware replacement. By leveraging dual CPU redundancy, the unit ensures deterministic performance and rapid failover in the event of a primary processor fault. The integrated interface suite facilitates seamless integration into existing industrial Ethernet and fieldbus topologies while maintaining isolation from potential electrical noise inherent in high-density control cabinets.

Frequently Asked Questions

Q: Does the PM851AK01 support live insertion (hot-swapping) in a redundant CPU pair?

A: The module supports redundancy switchover, but physical insertion or removal should only occur when the module power is removed or the specific rack segment is isolated. Live removal without proper software-initiated de-activation can lead to backplane bus disturbance.

Q: How does the module maintain synchronization in a redundant configuration?

A: Synchronization is handled via a dedicated high-speed link between the primary and backup CPUs. This link ensures that state data and control outputs remain identical across both modules, allowing the standby unit to take control in a single processor cycle during a fault event.

Field Installation Guidelines

• Mounting Procedure: Secure the PM851AK01 to the AC 800M base plate using the integrated fastening mechanism. Ensure the module is fully seated to guarantee proper engagement with the backplane connectors.
• Grounding Requirements: Connect the base plate ground lug to the cabinet reference ground using a minimum 2.5 mm square copper conductor. This provides the necessary discharge path for transient surge events.
• Cable Management: Utilize shielded twisted-pair cabling for all Ethernet and PROFIBUS connections. Separate communication lines from AC power and high-current DC field loops by at least 200 mm to minimize electromagnetic coupling.
• Environmental Sealing: Ensure the installation enclosure provides adequate ventilation. Although the module is rated for operation up to 60 deg C, excessive ambient heat buildup can reduce the lifespan of the internal memory components.