ABB PM861AK02 (Order Code: 3BSE018160R1) Redundant Processor Unit

1. Key Parameters

• Product Model: PM861AK02
• Order Code/Part Number: 3BSE018160R1 (unique identifier for procurement and system compatibility)
• Product Series: AC 800M DCS (ABB’s modular distributed control system for industrial automation)
• Core Function: Redundant processing backup for AC 800M systems; provides automatic failover, synchronized data processing, and uninterrupted control during primary CPU faults
• Processor & Performance:
  • CPU: 32-bit RISC processor (800MHz clock speed)
  • Control Cycle: Configurable from 1ms to 1000ms (deterministic, jitter ≤100µs)
  • Program Memory: 8MB Flash (for control programs and configuration data)
  • Data Memory: 4MB RAM (for real-time data processing and temporary variables)
  • Floating-Point Performance: 100 MFLOPS (supports complex control algorithms)
• Redundancy Features:
  • Redundancy Type: 1:1 hot standby (primary/secondary configuration)
  • Failover Time: ≤100ms (automatic switchover without process disruption)
  • Data Synchronization: Real-time mirrored memory between primary and redundant units (zero data loss during failover)
  • Heartbeat Monitoring: Continuous health checks between units (10ms interval)
• I/O & Communication:
  • Backplane Interface: ABB PRONETA bus (100Mbps) for communication with I/O modules; supports up to 16 I/O modules per rack
  • Maximum I/O Capacity: Up to 4096 digital I/O points or 1024 analog I/O points (via expansion)
  • Communication Ports: 2× 10/100BASE-T Ethernet ports (Modbus-TCP, Profinet); 1× RS-485 (Modbus RTU)
• Power Supply:
  • Input Voltage: 24V DC (±10% tolerance)
  • Redundant Power Inputs: 2× isolated power connections (prevents single-point power failures)
  • Typical Power Consumption: ≤12W
• Mechanical Specifications:
  • Dimensions (W×H×D): 25mm × 100mm × 160mm (1-module width, fits AC 800M standard racks)
  • Mounting: Rack-mounted (hot-swappable in redundant configurations)
  • Weight: Approximately 200g
• Environmental Ratings:
  • Operating Temperature Range: -25℃~+70℃ (-13℉~158℉)
  • Storage Temperature Range: -40℃~+85℃ (-40℉~185℉)
  • Humidity Tolerance: ≤95% RH (non-condensing, 40℃)
  • Vibration Resistance: 10~500Hz, 2g acceleration (IEC 60068-2-6)
  • Shock Resistance: 30g acceleration (11ms duration, IEC 60068-2-27)
• Compliance Standards: IEC 61131-3 (industrial programming), IEC 61000-6-2 (EMC immunity), UL 508 (industrial control safety)

2. Key Features

• Seamless Hot Standby Redundancy: Operates as a secondary processor in a 1:1 configuration with a primary PM861 processor. Automatically detects primary unit faults (e.g., processor failure, communication loss) and switches to active control in ≤100ms—ensuring zero process interruption in critical applications like power generation or chemical processing.
• Real-Time Data Synchronization: Mirrors all control logic, I/O data, and status variables between primary and redundant units via high-speed memory synchronization. Eliminates data loss during failover, maintaining process integrity and avoiding costly restarts.
• Deterministic Control Performance: 800MHz RISC processor and configurable 1ms control cycles ensure precise execution of control algorithms (PID, sequential logic, cascade control)—suitable for both steady-state processes (e.g., water treatment) and dynamic processes (e.g., turbine control).
• Dual Communication Interfaces: Equipped with Ethernet and RS-485 ports supporting industry-standard protocols (Modbus-TCP, Profinet, Modbus RTU). Enables redundant communication paths to SCADA systems, HMIs, and field devices—further enhancing system reliability.
• Hot-Swappable Design: Allows removal and replacement of the redundant unit while the system is operational. Facilitates maintenance without disrupting the primary processor or process control—critical for 24/7 operations in refineries or pharmaceutical plants.
• Comprehensive Diagnostics: Monitors internal health (processor temperature, memory status) and redundancy status (synchronization quality, failover history). Diagnostics data is transmitted to ABB’s Control Builder M software for proactive fault detection and troubleshooting.
• Industrial-Grade Durability: Withstands extreme temperatures (-25℃~+70℃), vibration, and humidity—ensuring reliable performance in harsh environments such as mining sites, offshore platforms, and steel mills.

3. Application Fields

• Power Generation: Ensures uninterrupted control of boilers, turbines, and grid-connection systems in thermal, nuclear, and renewable energy plants—preventing power outages during CPU failures.
• Oil & Gas Processing: Manages refineries, pipeline pumping stations, and offshore platforms—where downtime could lead to safety hazards, environmental risks, or significant production losses.
• Chemical & Pharmaceutical Manufacturing: Controls continuous reactors, batch processing systems, and purification lines—maintaining strict process parameters (temperature, pressure, pH) to ensure product quality and regulatory compliance (FDA, GMP).
• Water & Wastewater Treatment: Operates critical infrastructure such as pumping stations and filtration systems—avoiding service disruptions that could impact public health or environmental compliance.
• Mining & Metals: Controls crushers, conveyor belts, and smelting processes in harsh, remote environments—where maintenance access is limited and system reliability is paramount.
• Marine & Offshore: Manages shipboard systems (engine control, cargo handling) and offshore rigs—withstanding salt spray, vibration, and temperature extremes while ensuring safe operation.

4. Precautions

• Redundancy Pair Compatibility: Must be paired with a primary PM861 processor of the same firmware version. Mismatched firmware will cause synchronization failures and prevent proper failover.
• Synchronization Setup: Ensure the primary and redundant units are configured with identical control logic, I/O mappings, and communication settings via Control Builder M. Configuration mismatches will lead to data desynchronization.
• Power Supply Redundancy: Connect to separate, isolated 24V DC power sources for the primary and redundant units. Shared power supplies create a single point of failure, defeating redundancy purposes.
• Communication Network Redundancy: Use redundant Ethernet switches and separate cable paths for primary and redundant communication links. This prevents network faults from affecting both processors.
• Firmware Updates: Update firmware for both primary and redundant units simultaneously via Control Builder M. Updating one unit at a time will cause temporary desynchronization and may trigger unnecessary failovers.
• Environmental Protection: Install in a sealed, climate-controlled cabinet in harsh environments. Avoid exposure to corrosive gases (e.g., sulfur dioxide, salt spray) or temperatures outside the -25℃~+70℃ range.
• Hot-Swap Procedure: Follow ABB’s recommended hot-swap steps (disable redundancy via software before removal) to avoid transient faults. Never force the module into the rack—misalignment can damage the backplane connector