ABB | PM858K02 (3BSE082896R1) | AC800M Redundant Processor Unit

Product Description

The PM858K02 (3BSE082896R1) redundant processor unit is part of ABB’s AC800M controller family, engineered for high-availability automation systems. It combines fast cycle execution, robust communication protocols, and redundancy features to ensure continuous operation in demanding industrial environments.

Technical Specifications

• Processor: MPC866 embedded CPU

• Redundancy Switch-over Time: ≤ 10 ms

• Application Handling:

• 32 applications per controller

• 64 programs per application

• 128 diagrams per application

• 32 tasks per controller

• Cycle Times:

• 32 configurable cycle times

• Minimum cycle time down to 1 ms

• Firmware Storage: 4 MB Flash PROM

• Power Supply: 24 V DC (range 19.2–30 V DC)

• Power Consumption: Typical 210 mA, maximum 360 mA

• Power Dissipation: 5.1 W (maximum 8.6 W)

• Redundant Power Input: Supported

• Backup Battery: Lithium 3.6 V

• Clock Synchronization: 1 ms accuracy via CNCP protocol

• Event Handling:

• Up to 3000 events per OPC client

• Transmission speed: 36–86 events/sec, 113–143 data messages/sec

• Communication Modules (CEX bus): Up to 12 modules, max 2.4 A supply current

• I/O Clusters:

• Non-redundant CPU: 1 electrical + 7 optical

• Redundant CPU: 7 optical

• I/O Capacity: Max 96 modules (single PM866) or 84 modules (redundant PM866)

• Modulebus Scan Rate: 0–100 ms (depending on I/O count)

• Electrical Modulebus Supply Current:

• 24 V: max 1.0 A

• 5 V: max 1.5 A

• Ethernet:

• 2 channels, IEEE 802.3 standard

• 10 Mbit/s, RJ-45 (8-pole female)

• Control Network Protocols: MMS and IAC

• Recommended Backbone: 100 Mbit/s switched Ethernet

• Real-time Clock Stability: 100 ppm (~1 h/year)

• RS-232 Interfaces:

• 2 ports (general + service tool)

• COM3 (non-redundant only): 75–19,200 baud, RJ-45, full RTS-CTS support

• COM4 (non-redundant only): 9,600 baud, RJ-45, opto-isolated, no RTS-CTS support

Application Scenarios

• Redundant CPU configurations for mission-critical process industries

• OPC-based event-driven automation systems

• Distributed control networks requiring synchronized cycle times

FAQ

Q: How fast is the redundancy switch-over?  A: The PM858K02 achieves a maximum of 10 ms switch-over, ensuring minimal disruption.

Q: What is the maximum I/O capacity supported?  A: Up to 96 modules with a single PM866, or 84 modules in redundant PM866 configurations.

Q: Can the unit synchronize with other AC800M controllers?  A: Yes, synchronization accuracy is 1 ms using CNCP protocol.

Q: How does PM858K02 differ from PM858AK01?  A: PM858K02 is optimized for redundancy and event handling, while PM858AK01 is a CPU board variant with similar architecture but different integration scope.