ABB PM891 Processor Unit – High-Performance CPU with CEX-Bus and Redundancy Support

The ABB PM891 is a powerful and compact processor unit designed for high-availability applications in industrial automation. This monolithic processor integrates a power supply, CPU board, and unit termination, making it ideal for demanding control systems.

The PM891 features an onboard microprocessor, RAM memory, a real-time clock, LED status indicators, an INIT push button, and a Secure Digital (SD) interface. Engineered for reliability, it includes no internal battery and offers extensive network connectivity, with two RJ45 Ethernet ports (CN1, CN2) for Control Network integration and an isolated serial port (COM4) for configuration tools.

Key Features:

• Dual Ethernet ports for network redundancy and communication

• Isolated COM4 serial port for secure configuration

• Supports CPU redundancy for maximum system uptime

• Integrated CEX-Bus for communication expansion

• Compatible with redundant communication interfaces

• Optical Modulebus for connecting up to seven S800 I/O clusters

• Unique Ethernet address for hardware identification

The PM891 processor supports modular scalability via the CEX-Bus, enabling the connection of multiple communication interface units. Use of the BC810 CEX-Bus Interconnection Unit increases system availability by segmenting the bus.

Ideal for applications requiring flexible expansion, real-time control, and high fault tolerance, the PM891 ensures efficient automation performance with minimal downtime.