Description
📌 Product Overview
The WESDAC D20ME II is a main processor board designed for the D20 and D200 Substation Automation and Remote Terminal Unit platforms. It functions as the central processing and data concentration board, collecting information from field devices, processing system data, and communicating with SCADA or host systems.
The D20ME II acts as the master controller for D20 peripheral I/O modules. It supports local automation functions, database processing, communications, and maintenance operations within the substation automation system. The D20ME II is functionally similar to the earlier D20ME processor but adds the ability to select RS-232 or RS-485/RS-422 communication on a per-channel basis.
⚙️ Key Features
🧠 32-bit main processor architecture
📡 Central processor and data concentrator
🔌 Supports D20 and D200 automation platforms
🔄 Master controller for D20 peripheral I/O modules
💾 2 MB flash application memory
⚡ 1.5 MB SRAM
🔋 512 KB battery-backed NVRAM
📀 1 MB BootROM
⏱️ TCXO real-time clock with 1.0 ms resolution
📞 7 configurable serial communication channels
🔁 Per-channel RS-232 or RS-485/RS-422 interface selection
🏭 Designed for SCADA and substation automation applications
🛠️ Supports local automation and field data processing
📋 Product Datasheet
🏷️ Brand: WESDAC / GE Digital Energy
🔢 Model: D20ME II
🧩 Product Type: Main CPU Board / Main Processor
📚 Series: D20 / D200
⚙️ Processor Architecture: 32-bit
💾 Flash Application Memory: 2 MB
🧠 SRAM: 1.5 MB
🔋 NVRAM: 512 KB
📀 BootROM: 1 MB
⏱️ Clock Resolution: 1.0 ms
🎯 Clock Accuracy: ±2 ppm
📡 Serial Ports: 7 communication channels
🔌 Serial Interface: RS-232 or RS-485/RS-422 selectable per channel
🖥️ Primary Function: Data concentration and central processing
🔄 I/O Architecture: Master controller for D20 peripheral I/O modules
🏭 Application: SCADA / RTU / Substation Automation
🧱 Installation Type: D20 or D200 chassis configuration dependent
📦 Hardware Versions: VME and non-VME versions available
The documented D20ME II board versions include part numbers 526-2006 for the non-VME configuration and 526-2007 for the VME configuration. The exact board part number should be confirmed from the physical unit before listing or installation.
🏭 Typical Applications
⚡ Electrical Substations
The D20ME II can be used as the central processor in substation automation systems for collecting and processing field information.
📡 SCADA Systems
The board concentrates data from connected equipment and forwards processed information to supervisory SCADA systems.
🔄 Remote Terminal Units
Used within D20 and D200 RTU architectures where centralized processing and communication with distributed I/O devices are required.
🏗️ Utility Automation
Suitable for power transmission and distribution environments requiring communication between substation equipment and central control systems.
🛠️ Legacy System Maintenance
The D20/D200ME product family is primarily encountered in installed-base maintenance and spare-parts applications. GE Vernova has issued end-of-manufacturing and supply notices for the D20/D200ME portfolio, making verified replacement hardware important for existing systems.
🔧 Installation and Replacement Notes
Before installing a replacement D20ME II board, verify the exact processor configuration and chassis type.
🔧 Confirm whether the existing system requires a VME or non-VME version.
🔧 Check the physical board part number, such as 526-2006 or 526-2007.
🔧 Record existing jumper and communication settings before removing the original board.
🔧 Verify RS-232 and RS-485/RS-422 interface configuration for each required communication channel.
🔧 Check firmware and application compatibility with the installed D20/D200 system.
🔧 Inspect board connectors and chassis contacts before installation.
🔧 Verify the NVRAM battery condition on stored or long-term spare boards.
🔧 After installation, check communication with peripheral I/O modules and the SCADA host.
🔧 Confirm database operation and local automation functions before returning the system to service.
⚠️ The D20ME II should not be replaced solely by matching its physical appearance. The VME/non-VME configuration, firmware, communication settings, and installed chassis architecture must also be verified.
❓ FAQ
Q: What is the WESDAC D20ME II?
A: It is the main processor and central CPU board used in WESDAC D20 and D200 substation automation systems.
Q: What is the main function of the D20ME II?
A: It acts as a data concentrator and central processor, collecting field data, processing system information, communicating with host systems, and controlling D20 peripheral I/O modules.
Q: Is D20ME II different from D20ME?
A: Yes. The D20ME II is functionally similar to the D20ME but adds per-channel selection between RS-232 and RS-485/RS-422 communication interfaces.
Q: How many serial communication channels are available?
A: The D20ME II provides seven configurable serial communication channels, while a separate maintenance interface is used for system maintenance functions.
Q: Does the D20ME II support both RS-232 and RS-485?
A: Yes. One of its key features is the ability to select RS-232 or RS-485/RS-422 operation on a per-channel basis.
Q: Is the D20ME II a PLC CPU?
A: It is better described as a main processor for a substation automation and RTU platform rather than a conventional PLC CPU.
Q: What is the difference between the VME and non-VME versions?
A: The VME version is designed for D20/D200 VME chassis applications and can support VME-based expansion functions, while the non-VME version is intended for single-processor D20 configurations.
Q: Which part numbers are associated with D20ME II?
A: Documentation identifies 526-2006 as a non-VME D20ME II version and 526-2007 as a VME D20ME II version.
Q: What should I verify before purchasing a replacement?
A: Check the exact board part number, VME or non-VME configuration, firmware, memory configuration, communication interface settings, chassis compatibility, and physical condition.
🔄 Other WESDAC D20 / D200 Models
- WESDAC D20ME — Main Processor Board
- WESDAC D20ME II 526-2006 — Non-VME Main Processor
- WESDAC D20ME II 526-2007 — VME Main Processor
- WESDAC D20EME — Ethernet Memory Expansion Module
- WESDAC D20EME2 — Ethernet Memory Expansion Card
- WESDAC D200 — Substation Automation Platform
- WESDAC D20 — Substation Controller
- WESDAC D20 Peripheral I/O Module — Remote I/O Module
- WESDAC D20 Media Interface Card — Network Interface Module
- WESDAC Universal Protocol Converter — Protocol Conversion Module
🏷️ Recommended Short Title
WESDAC | D20ME II | D20/D200 Main CPU Board
