Brief Product Description

PM866AK01, part number 3BSE076939R1, is a high-performance core processor unit for ABB AC 800M and System 800xA DCS platforms. Equipped with a 133 MHz high-speed processor and 64 MB RAM, this rack-mounted CPU delivers fast deterministic real-time control with minimum 1 ms cycle time. Supporting redundant control configuration, hot-swap capability and conformal-coated PCB design, it executes complex process control logic, handles massive I/O data processing and ensures stable 24/7 operation for medium and large-scale industrial automation systems. It serves as a critical spare replacement part for legacy ABB DCS system maintenance and upgrades.

Item Details

Product Number 3BSE076939R1

ABB Model Name PM866AK01

Directory Description PM866AK01 processor unit

Included Components - PM866A CPU

                       - TP830 Base Plate

                       - TB850 CEX Bus Terminal

                       - TB807 ModuleBus Terminal

                       - TB852 RCU-Link Terminal

                       - Memory Backup Battery (4943013-6)

Core Product Functions

• 133 MHz high-speed processing core executing complex industrial control algorithms and logic programs
• 64 MB built-in RAM and CompactFlash interface for program storage and data caching
• Dual Ethernet ports and dual serial communication interfaces for redundant network data transmission
• Real-time I/O data acquisition, calculation and closed-loop control for S800 series I/O modules
• Supports 1+1 redundant CPU configuration for bumpless switchover and maximum system availability
• Ultra-fast logic operation speed, completing 1000 Boolean operations within 0.09 ms
• Comprehensive on-board self-diagnostics, fault alarm and event timestamp recording function
• Hot-swap support allows module replacement without shutting down the entire control rack
• Conformal coated PCB provides excellent protection against humidity, dust and EMI interference

• Seamless compatibility with ABB Control Builder M engineering software for configuration and debugging

  
  

Application Scenarios

• Thermal power, hydroelectric and combined-cycle power plant DCS process control systems
• Oil & gas onshore/offshore platform and petrochemical refinery automation control racks
• Chemical, pulp & paper and metallurgical large-scale continuous process production lines
• Water treatment, municipal utility and industrial boiler monitoring and control systems
• Medium and large-scale factory intelligent automation and safety instrumented control platforms
• Retrofit, expansion and maintenance spare processor for existing ABB 800xA / AC800M DCS installations

FAQ (Frequently Asked Questions)

• Q: Module fails to start or reports CPU fault after power-on?
  A: Check rack backplane contact stability, 24VDC power supply quality, firmware version matching, configuration file integrity or aging internal memory components.
• Q: System communication is intermittent and control loop response delays?
  A: Inspect network cable connection, Ethernet port status, excessive system load, cabinet overheating or electromagnetic interference.
• Q: Does PM866AK01 support hot-swap during system running?
  A: Yes, hot-swap is supported. For redundant systems, replacement can be done online; single CPU configuration requires prior safety interlock suspension.
• Q: Can this processor unit work with other brands of PLC or DCS systems?
  A: It is exclusively designed for ABB AC 800M / 800xA DCS platforms, and does not support cross-brand or cross-system compatibility.

• Q: Is 3BSE076939R1 available for new DCS construction projects?
  A: This legacy processor unit has reached end-of-life. Only surplus, tested and refurbished spare modules are provided for existing system maintenance and retrofit.

PM866AK01 3BSE076939R1 Processor Unit.pdf