Honeywell TK-PRS021 Control Processor Module (Correction: Not Power Module)

Critical Note

Basic Product Information

• Model: TK-PRS021
• Factory part codes: 51404305-375 / 51404305-475
• Series: Experion PKS C200 / C200E process controller CPU
• Mounting: Single-slot plug-in for C200 rack backplane
• Weight: ~0.5 kg
• Status: Discontinued original production, only refurbished/spare stock available for legacy DCS maintenance

Core Hardware & Performance Parameters

1. Computing & Memory

• Main processor: 200MHz high-speed industrial microcontroller
• Flash storage: 1MB (store control logic, recipes, configuration)
• Running RAM: 512KB (real-time process data cache)
• Scan speed: Millisecond-level deterministic control cycle for continuous process loops

2. Power Requirements (CPU Internal Power Rail)

• External input power: 18–32 VDC nominal 24VDC
• Internal generated power for backplane:
   
  +5VDC @1.5A, +3.3VDC @1.0A
• Built-in non-rechargeable lithium backup battery:
   
  Retains program & data for up to 144 hours (6 days) during rack power failure
   
  Optional BEM battery extension module extends backup duration to 120 hours rechargeable power

3. Communication Interfaces

• 2 × Independent Ethernet ports (Modbus TCP, Experion proprietary UCN protocol, HMI station connection)
• 1 × RS232 serial port (PC programming download via Control Builder software)
• Dedicated redundancy sync port (pair with TK-PRR021 redundancy module for 1:1 hot standby CPU)
• Backplane bus interface for I/O module data exchange

4. Environmental & Protection

• Operating temperature: 0℃ ~ +60℃; storage: -40℃ ~ +85℃
• Humidity: 5%–95% RH non-condensing
• TK version feature: PCB conformal coating, anti-moisture, dust, chemical vapor for coastal/chemical corrosive cabinets
• Certifications: CE, UL, TÜV, SIL2 safety compliance for general process control loops

Front Panel Indicator & Function

• Multi-status LED group: PWR, RUN, COMM, FAULT, REDUNDANCY status
• Built-in reset button for CPU cold restart
• Flip cover for battery replacement without removing module from rack

Core Working Functions

1. Execute all DCS control logic: PID regulation, sequence control, interlock logic, alarm management
2. Collect all rack I/O module analog/digital signals via backplane bus
3. Real-time data exchange with operator stations, HMI, upper-level SCADA via Ethernet
4. Support hot standby redundancy: Pair two TK-PRS021 + two TK-PRR021 redundancy modules
5. Store historical trend data, event logs, fault records locally
6. Real-time self-diagnosis of CPU hardware, communication bus, battery health

Complete Redundant System Matching List

• 2 × TK-PRS021 main CPU processors
• 2 × TK-PRR021 redundancy synchronization modules
• Dedicated redundancy sync cable
• Dual redundant rack power supply modules
• Mixed AI/AO/DI/DO I/O modules on shared backplane rack

Key Advantages

1. Conformal coated circuit board, suitable for refinery, chemical plant harsh corrosive environments
2. Millisecond-level bumpless failover when deployed in redundant configuration
3. Long-term battery data backup, no program loss during short power outages
4. Dual Ethernet ports support network redundancy to avoid single communication point failure
5. Hot-swap design: Replace CPU online without rack full power cut
6. Full hardware self-diagnosis, quickly locate CPU, communication, battery abnormal faults

Typical Application Scenarios

• Petrochemical refinery, natural gas processing core DCS control racks
• Thermal power boiler, turbine auxiliary process control systems
• Chemical reaction tank, batch production automatic control
• Water treatment & sewage plant central process monitoring
• Fertilizer, coal chemical, pharmaceutical continuous production lines
• All industrial sites using Honeywell Experion PKS C200 DCS platform