ABB | PM858 (3BSE093350R1) | Processor Unit AC800M

Product Description

The PM858 (3BSE093350R1) processor unit is part of ABB’s AC800M controller family, designed to provide reliable computing performance for distributed control systems. It supports multiple applications, fast cycle times, and robust communication interfaces, making it suitable for high-demand industrial automation environments.

Technical Specifications

• Processor: MPC866 embedded CPU

• Redundancy Switch-over Time: ≤ 10 ms (in redundant configurations)

• 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)

• 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 many applications can the PM858 handle?  A: Up to 32 applications per controller, with 64 programs per application.

Q: What is the redundancy switch-over time?  A: Maximum 10 ms, ensuring minimal disruption in redundant setups.

Q: How does PM858 compare to PM866?  A: PM858 is optimized for redundancy and synchronization, while PM866 supports higher I/O capacity in single configurations.

Q: What communication protocols are supported?  A: MMS and IAC, with Ethernet IEEE 802.3 standard interfaces.