Product Core Brief
- Part Number: 820-0474
- Label Reference: D20 EME 10BASE-T 820-0474
- Brand: GE (GE Energy / GE Digital)
- Series: GE D20 / D200 RTU
- Core Function: D20 EME (Ethernet/Memory Expansion) board for GE D20/D200 substation RTU systems, providing Ethernet communication via a 10BASE-T MIC and optional global memory expansion.
- Product Type: D20/D200 Ethernet & Memory Expansion Board
- Key Specs: 10BASE-T Ethernet | MIC-based media interface | global memory expansion option | D20/D200 RTU compatible | VME chassis support | self-configuring board | legacy/obsolete product
- Condition: New Original / New Surplus
Product Introduction
GE D20 EME 10BASE-T 820-0474 is an Ethernet/Memory Expansion (EME) board for the GE D20/D200 remote terminal unit family. The D20 EME platform adds Ethernet connectivity and/or global memory expansion to D20 and D200 RTU systems, which are widely deployed in substation automation, SCADA, and distribution automation applications.
The “10BASE-T” designation indicates this board is configured with a 10BASE-T Media Interface Card (MIC), providing a standard twisted-pair RJ-45 Ethernet port at 10 Mbps. The EME board itself is described in GE D20/D200 documentation as a self-configuring product: the main board has no jumpers or switches to define VME interrupts, Ethernet bus address, or similar parameters.
Memory options for the D20 EME family have included 0 MB, 8 MB, or 16 MB of battery-backed SRAM, but the exact memory configuration for 820-0474 should be confirmed from the board label and revision.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Manufacturer | GE (GE Energy / GE Digital) |
| Part Number | 820-0474 |
| Label Reference | D20 EME 10BASE-T |
| Product Type | D20/D200 Ethernet & Memory Expansion Board |
| Series | GE D20 / D200 RTU |
| Typical Application | Substation automation, SCADA, distribution automation |
| Ethernet Interface | 10BASE-T MIC (RJ-45, twisted-pair, 10 Mbps) |
| Memory Option | Battery-backed SRAM (0 / 8 / 16 MB, to be confirmed) |
| Compatible Chassis | D20 horizontal-slot chassis, D200 vertical-slot chassis |
| Configuration | Self-configuring; no jumper-defined Ethernet/VME parameters |
| Status | Legacy / Obsolete |
Note: Public documentation confirms the D20 EME family and its 10BASE-T variant, but the exact memory size, revision, and supported protocols for 820-0474 should be verified from the board label and the GE D20/D200 Installation and Operations Guide before commissioning.
Quality Control Process (DYNAMIC GENERATION)
- Visual and connector inspection. We check the board, VME edge connector, 10BASE-T MIC module, RJ-45 port, LEDs, battery, and mounting hardware for damage or corrosion.
- Continuity and insulation check. Key power paths, VME bus pins, and MIC connectors are verified for correct continuity and no short circuits.
- System compatibility check. The part number, revision, and 10BASE-T MIC are matched against the D20/D200 chassis, D20ME/D20ME II processor board, and existing configuration.
- Power-up and diagnostic check. Where a compatible D20/D200 test setup is available, the board is checked for proper power-up, memory recognition, and 10BASE-T link status.
- Final packaging. After passing inspection, the board is anti-static bagged and foam-packed for shipment.
Replacement Pitfall Guide (DYNAMIC GENERATION)
❗ Confirm memory configuration. D20 EME boards were offered with 0, 8, or 16 MB battery-backed SRAM; verify the installed memory matches your system requirement.
❗ Verify the 10BASE-T MIC is installed. The EME board requires the correct MIC for the physical Ethernet port; a board without the MIC will not provide an RJ-45 connection.
❗ Check chassis compatibility. D20 EME boards are used in D20/D200 VME-compatible chassis; they are not interchangeable with PACSystems RX3i, PAC8000, or Series 90 modules.
❗ Do not confuse with a processor or I/O module. The EME board provides Ethernet/memory expansion, not field I/O or CPU processing.
❗ Match processor board and firmware. The D20ME/D20ME II processor board, BootROM type, and Config Pro settings must support the installed EME configuration.
❗ Handle as ESD-sensitive equipment. Always use anti-static handling procedures during removal, installation, and storage.
Keep these in mind and you’ll cut 90% of rework time.
Compatibility Matrix & Benchmarks
| Original Model | Replacement / Successor Model | Compatibility Level | Migration Notes |
|---|---|---|---|
| GE D20 EME 10BASE-T 820-0474 | GE D20 EME 10BASE-T 820-0474 | Direct | Same part number; verify revision, memory size, and MIC. |
| GE D20 EME 10BASE-T 820-0474 | Other D20 EME variants (10BASE-FL, 10BASE2) | Needs Adaptation | Different MIC type; requires matching physical media. |
| GE D20 EME 10BASE-T 820-0474 | D20ME / D20ME II processor board | Not Compatible | Processor board and EME expansion board serve different functions. |
| GE D20 EME 10BASE-T 820-0474 | PACSystems / PAC8000 modules | Not Compatible | Different platform, backplane, and RTU architecture. |
Benchmark highlights
- D20 EME expansion board for GE D20/D200 RTU systems.
- 10BASE-T Ethernet via MIC (RJ-45, twisted-pair, 10 Mbps).
- Optional battery-backed SRAM expansion (0 / 8 / 16 MB).
- Self-configuring board with no jumper-defined Ethernet/VME parameters.
- Suitable for substation automation, SCADA, and distribution automation.
- Legacy product; best suited for existing D20/D200 system upgrades and like-for-like replacement.
