GE D20EME10BASE-T 820-0474 – Ethernet Interface Module for GE D20 RTU Networks

The GE D20EME10BASE-T (P/N 820-0474) is a legacy Ethernet module designed for the GE D20/D200 RTU platform. From my experience, this is the straightforward way to bring 10BASE‑T (RJ45) network connectivity to an existing D20 chassis without re-architecting your substation or plant network. It’s typically used to connect the D20 to SCADA hosts, engineering workstations, or substation LANs where 10 Mbps links are still supported.

One thing I appreciate is how predictable it behaves in brownfield environments—no surprises with auto‑negotiation. It’s a fixed 10 Mbps Ethernet interface, which in many cases makes it easier to integrate with managed switches configured for legacy devices. You might notice that spares like this keep fleets running, especially where protocol stacks reside on the D20 CPU and the Ethernet card’s job is to provide a stable physical link.

Company’s Order Placement Process and Guarantees

• Warranty period: 365 days
• Delivery lead time: 1 week if in stock; not more than one month at the latest
• Payment: 50% advance payment; full payment prior to delivery
• Express options: FedEx, UPS, DHL

Key Features

• 10BASE‑T Ethernet (RJ45) – Fixed 10 Mbps twisted‑pair interface for legacy/utility networks.
• Seamless D20 integration – Plugs into the D20 chassis; power and data via backplane, no external supply.
• Stable link for SCADA – Provides the physical network layer used by the D20 application (e.g., DNP3 over TCP/IP or Modbus TCP, depending on your D20 firmware configuration).
• Service-friendly – Front‑access RJ45 port with link/activity indication makes field checks quicker.
• Proven in substations – In most cases used in transmission/distribution sites where deterministic, fixed‑rate links are preferred.

Technical Specifications

Brand / Model	GE D20EME10BASE-T (Part No. 820-0474)
HS Code	8538.90 (Parts for switchgear/control panels)
Power Requirements	Powered via GE D20 backplane; no external power input
Communication Interfaces	1 × RJ45 10BASE‑T Ethernet (10 Mbps)
Signal I/O Types	Ethernet link only; front‑panel link/activity LEDs
Installation Method	Plug‑in module for GE D20/D200 chassis; front‑access port
Dimensions & Weight	D20 rack card form factor; occupies one slot
Operating Temperature	Aligned with GE D20 chassis environmental rating
Compatibility	GE D20/D200 systems using Ethernet‑enabled applications on the CPU

Application Fields

Utilities typically use this module in substation automation, feeder automation, and legacy RTU upgrades where 10 Mbps links are maintained for determinism and device compatibility. It also shows up in:

• Transmission and distribution substations (D20 acting as a bay controller or data concentrator)
• Water & wastewater plants integrating older RTU networks to IP‑based SCADA
• Oil & gas pipeline and station telemetry where the D20 is retained as the primary I/O processor
• Industrial facilities with mixed vintage control rooms and managed switches supporting 10 Mbps

A maintenance engineer from a North American utility summed it up simply: “We keep a couple of D20EME10BASE‑T cards on the shelf. When a port goes intermittent, swapping this card gets the SCADA link back in minutes.”

Advantages & Value

• Risk‑free replacement – Drop‑in spare for existing GE D20 Ethernet slots limits outage time.
• Compatibility – Works with D20 firmware applications that already speak IP‑based SCADA protocols.
• Cost control – Extends asset life without forcing a platform migration or protocol gateway redesign.
• Supportable – Behavior is well known by substation teams; easier to troubleshoot than mixed‑speed links.

Installation & Maintenance

• Cabinet & environment – Install in a GE D20/D200 chassis within a clean, ventilated control cabinet. Keep ambient within the D20 chassis rating.
• Power‑down before service – From my experience, treating it as non‑hot‑swappable is the safe path. Power down the chassis before inserting or removing the module.
• Wiring – Use shielded Cat5e (or better) to a switch port locked to 10 Mbps. Avoid auto‑negotiation mismatches; fixed 10 Mbps usually gives a cleaner link.
• ESD handling – Observe grounding and ESD precautions during handling and installation.
• Configuration – IP addressing and protocol setup reside in the D20 CPU application; verify settings after hardware replacement.
• Routine checks – Inspect RJ45 terminations, confirm link/activity LED operation, and document switch port settings. Clean dust from front panel during scheduled maintenance.

Quality & Certifications

• Typically supplied for use in systems carrying CE and UL/cUL markings on the D20 platform
• Built for utility‑grade EMC/EMI environments associated with the GE D20 system
• Warranty: 365 days

Related Components (for planning)

• GE D20ME II CPU modules for application processing and protocol stacks
• GE D20 power supplies and chassis options (for capacity and spare slot planning)
• Managed Ethernet switches with fixed 10 Mbps port capability for deterministic links

If you’re refreshing spares or stabilizing a mixed‑vintage network, this D20EME10BASE‑T card tends to be the practical choice—simple, predictable, and easy for field teams to support.