ABB PM864AK02 (Order Code: 3BSE018164R1) Redundant Processor Unit 

1. Key Parameters

• Product Model: PM864AK02
• Order Code/Part Number: 3BSE018164R1 (unique identifier for procurement and system compatibility validation)
• Product Series: AC 800M DCS (ABB’s modular, scalable distributed control system for industrial automation)
• Core Function: 1:1 hot-standby redundancy for AC 800M primary processors; enables automatic failover, real-time data synchronization, and uninterrupted control during primary unit faults
• Processor & Performance:
  • CPU: 32-bit RISC processor (1.0GHz clock speed)
  • Control Cycle: Configurable from 1ms to 1000ms (deterministic, jitter ≤100µs for high-speed process control)
  • Program Memory: 12MB Flash (non-volatile; stores control programs, configuration data, and fault logs)
  • Data Memory: 6MB RAM (for real-time data processing, temporary variables, and synchronized status data)
  • Floating-Point Performance: 120 MFLOPS (supports complex control algorithms: PID, cascade control, fuzzy logic, and sequential function charts)
• Redundancy Features:
  • Redundancy Architecture: 1:1 hot standby (primary/secondary configuration)
  • Failover Time: ≤100ms (automatic switchover; no process disruption or data loss)
  • Data Synchronization: Real-time memory mirroring (10ms sync interval) between primary and redundant units; ensures identical control logic, I/O data, and system status
  • Heartbeat Monitoring: Continuous health checks (5ms interval) for primary unit faults (e.g., processor failure, communication loss, overheating)
• I/O & Communication:
  • Backplane Interface: ABB proprietary PRONETA bus (100Mbps full-duplex); supports up to 24 AC 800M-compatible I/O modules per rack
  • Maximum I/O Capacity: Up to 6144 digital I/O points or 1536 analog I/O points (via expansion racks)
  • Communication Ports:
    • 2× 10/100BASE-T Ethernet ports (supports Modbus-TCP, Profinet, IEC 61850 GOOSE for SCADA/HMI integration)
    • 1× RS-485 port (Modbus RTU for local field device communication)
    • Optional: Profibus-DP master module (via expansion slot for third-party device connectivity)
• Power Supply:
  • Input Voltage: 24V DC (±10% tolerance)
  • Redundant Power Inputs: 2× isolated power connections (prevents single-point power failures)
  • Power Consumption: Typical ≤15W; Maximum ≤20W
• Mechanical Specifications:
  • Dimensions (W×H×D): 25mm × 100mm × 160mm (1-module width; fits AC 800M standard I/O racks)
  • Mounting: Rack-mounted (hot-swappable in redundant configurations)
  • Weight: Approximately 210g
• 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 controller programming), IEC 61000-6-2 (EMC immunity), UL 508 (industrial control safety), IEC 61508 (functional safety for SIL 2 applications)

2. Key Features

• Seamless Hot-Standby Redundancy: Operates as a passive secondary unit until a primary fault is detected, then switches to active control in ≤100ms. This zero-downtime failover is critical for processes like nuclear power plant control or chemical reactor management, where even short interruptions risk safety hazards.
• Real-Time Memory Mirroring: Synchronizes all critical data (control logic, I/O values, alarm status, and process variables) with the primary unit at 10ms intervals. Eliminates data loss during failover, ensuring process continuity and avoiding costly restarts or product defects.
• Deterministic High-Speed Control: 1.0GHz RISC processor and 1ms configurable control cycles enable precise execution of dynamic control tasks—e.g., turbine speed regulation in power plants or pressure control in petrochemical reactors—without compromising redundancy.
• Multi-Protocol Communication Redundancy: Dual Ethernet ports support redundant communication paths to SCADA systems, HMIs, and field devices. If one Ethernet link fails, the unit automatically switches to the backup path, further enhancing system reliability.
• Hot-Swappable Design: Allows removal and replacement of the redundant unit while the system is operational. Facilitates maintenance (e.g., firmware updates, component checks) without disrupting the primary processor or industrial processes—essential for 24/7 operations like oil refineries or pharmaceutical batch processing.
• SIL 2 Functional Safety Compliance: Meets IEC 61508 SIL 2 requirements, making it suitable for safety-critical applications (e.g., emergency shutdown systems, fire suppression controls) where hardware reliability directly impacts personnel or environmental safety.
• Advanced Diagnostics & Fault Logging: Monitors internal health (processor temperature, memory integrity, power supply status) and redundancy performance (sync quality, failover history). Faults are logged with time stamps and transmitted to ABB’s Control Builder M software, enabling predictive maintenance and root-cause analysis.

3. Application Fields

• Power Generation (Critical Units): Protects control systems for nuclear reactors, thermal power plant boilers, and large-scale wind/solar farms—ensuring grid stability and preventing power outages during processor faults.
• Oil & Gas (Upstream/Downstream): Manages offshore drilling rigs, crude oil refineries, and natural gas processing plants—where downtime can cost millions in lost production or trigger environmental incidents (e.g., oil spills).
• Chemical & Pharmaceutical (Continuous Processes): Controls petrochemical crackers, polymer reactors, and sterile pharmaceutical manufacturing lines—maintaining strict process parameters (temperature, pressure, pH) to ensure product quality and regulatory compliance (FDA, GMP).
• Water & Wastewater (Critical Infrastructure): Operates large municipal water treatment plants or wastewater pumping stations—avoiding service disruptions that risk public health or environmental contamination.
• Mining & Metals (Heavy Processing): Controls iron ore smelters, copper refineries, and underground mining conveyor systems—withstanding dust, vibration, and temperature extremes while ensuring uninterrupted production.
• Marine & Offshore (Safety-Critical Systems): Manages shipboard propulsion control, offshore platform emergency shutdown systems, and LNG carrier cargo handling—complying with maritime safety standards (SOLAS) and withstanding salt spray, humidity, and mechanical shock.

4. Precautions

• Redundancy Pair Compatibility: Must be paired with a primary AC 800M processor (e.g., PM864A) of the same firmware version. Mismatched firmware will cause synchronization failures, preventing proper failover and risking process disruption.
• Synchronization Configuration: Use ABB’s Control Builder M software to ensure identical control logic, I/O mappings, and communication settings for primary and redundant units. Configuration mismatches will break data mirroring and trigger false fault alarms.
• Redundant Power Supply Mandate: Connect primary and redundant units to separate, isolated 24V DC power sources (e.g., two independent power supplies in the control cabinet). Shared power supplies create a single point of failure, defeating the purpose of redundancy.
• Communication Network Redundancy: Deploy redundant Ethernet switches and separate cable paths for primary and redundant communication links. This prevents network faults (e.g., cable damage, switch failure) from disabling both processors.
• Firmware Update Protocol: Update firmware for primary and redundant units simultaneously via Control Builder M. Updating one unit at a time causes temporary desynchronization and may trigger unnecessary failovers. Always back up configuration data before updating.
• Environmental Protection: Install in a sealed, climate-controlled cabinet in harsh environments. For offshore or coastal applications, use corrosion-resistant racks and ensure the unit is protected from salt spray. Avoid temperatures outside the -25℃~+70℃ range.
• Hot-Swap Safety: Follow ABB’s official hot-swap procedure (disable redundancy via software before removing the unit) to avoid transient voltage spikes or data corruption. Never force the module into the rack—misalignment can damage the backplane connector or internal components