Description
The Wesdac D20ME (Part Number 820-0468/00) is a high-performance Processor Module serving as the central intelligence unit for the GE-Harris D20 distributed control and data acquisition system. This module is designed to handle complex communication protocols, execute real-time logic, and perform local data processing for substation automation, SCADA (Supervisory Control and Data Acquisition) networks, and remote terminal unit (RTU) applications. Its ruggedized design ensures operational reliability in harsh utility environments where electromagnetic interference and thermal fluctuations are common.
Key Technical Specifications
- Primary Function: Central processing for the D20 RTU platform; manages system configuration, I/O polling, and communication tasks.
- Operating System: Designed for high-speed, deterministic execution of control tasks and communication protocols.
- Connectivity: Features multiple serial and Ethernet ports to interface with external master stations, I/O subsystems, and local human-machine interfaces.
- Data Processing: Manages point databases, including real-time status updates, analog value scaling, and event time-stamping.
- Memory: Integrated non-volatile memory for storing firmware, project configurations, and event logs.
- Diagnostic Features: On-board LEDs and diagnostic buffers for monitoring CPU health, communication port activity, and peripheral status.
- Redundancy Support: Compatible with redundant D20ME configurations to provide seamless failover in critical utility infrastructure.
- Environmental Rating: Industrial-grade construction optimized for wide temperature ranges and high-EMI substation environments.
- Mounting: Designed for standard D20 rack-mount chassis integration.
- Firmware: Field-upgradable to support evolving protocol requirements or system enhancements.
Integration and Application
The D20ME processor module orchestrates the entire D20 rack. It functions as the master controller for all peripheral cards, ensuring that field data is accurately captured, processed, and transmitted to the centralized SCADA system. Key duties include:
- Protocol Conversion: Translating various field protocols (DNP3, Modbus, IEC 60870-5-101/104) into a unified format for system reporting.
- Logic Execution: Running user-defined programmable logic control (PLC) tasks for local automated switching or alarm generation.
- Time Synchronization: Maintaining precise system time-stamping (often via GPS/IRIG-B inputs) for sequence-of-event recording.
Related GE-Harris D20 Series Components
To maintain a fully operational D20 substation automation system, the D20ME is typically deployed alongside the following modules:
- D20S/D20KI: I/O modules for digital and analog data acquisition.
- D20K: Peripheral I/O controller module.
- D20 Base Chassis: The physical rack housing the processor and I/O cards.
- D20 Power Supply: Dedicated DC/DC converter module for the D20 rack.
- D20CI: Communication interface module for additional serial or fiber ports.
- D20 Link: Modules used for expanding the communication network across the substation.
- D20 VME/Bus Cables: Specialized backplane interconnects for module communication.
- Toolbox Software: The configuration environment used to build the RTU database and logic.
- D20M++: Successor processor module offering increased memory and processing capabilities.
- Analog Input/Output Cards: For precise control and monitoring of voltage and current levels.
