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Product Overview
The Reliance Electric 57C404C is a high-speed network communications module engineered by Reliance Electric (now part of Rockwell Automation) as a core component of the AutoMax and DCS 5000 distributed control architectures. As the “data switch” of the AutoMax system, the Reliance Electric 57C404C plugs directly into the backplane of an AutoMax rack and converts internal PLC data into a proprietary synchronous serial network protocol, enabling multiple AutoMax controllers and remote I/O racks to share control and status information in real time. The “C” revision denotes updated firmware for improved compatibility and reliability over earlier 57C404/57C404A/57C404B hardware.Physically, the Reliance Electric 57C404C is a printed circuit assembly with a front faceplate containing two D-shell connectors: a 9-pin “NETWORK” port for synchronous rack-to-rack communication, and a 25-pin “MONITOR” port providing an RS-232-compatible asynchronous link for local diagnostics. Two thumbwheel switches set the module’s unique drop number (node address), while a 7-segment LED displays numeric fault codes and a green status light indicates operational health. On the rear, dual edge connectors (P1/P2 female slots) mate with the AutoMax rack backplane. With a typical operating speed of 845 kbaud and support for network trunks up to 3000 ft, the Reliance Electric 57C404C delivers deterministic, low-latency data exchange across sprawling industrial sites.Manufactured in the USA and now discontinued (EOL), the Reliance Electric 57C404C remains a critical spare part for thousands of AutoMax systems still operating in metals, paper, material handling, and process industries worldwide. Drawing 5 V DC @ 2.5 A from the backplane, housed in a single-slot AutoMax form factor measuring approximately 229 × 51 × 152 mm and weighing 1.4 kg, with conformal coating for industrial environments and an operating range of 0°C to +60°C, the Reliance Electric 57C404C embodies the ruggedness and reliability that mission-critical legacy automation demands. Its tool-free ejector tabs allow rapid replacement in minutes, minimizing costly unplanned downtime.
Technical Specifications
| Parameter | Value |
|---|---|
| Product Model | 57C404C |
| Manufacturer | Reliance Electric (now Rockwell Automation) |
| Product Type | AutoMax Network Communications Module / Remote I/O Scanner |
| Compatible System | AutoMax / DCS 5000 Distributed Control System |
| Network Protocol | Reliance proprietary synchronous serial (AutoMax network) |
| Communication Speed | 845 kbaud (deterministic) |
| Max. Network Length | 3000 ft (per trunk) |
| Network Port | 9-pin D-shell “NETWORK” (synchronous serial) |
| Monitor Port | 25-pin D-shell “MONITOR” (RS-232C asynchronous) |
| Node Addressing | Dual thumbwheel switches (Drop Number, 2-digit) |
| Power Supply | 5 V DC @ 2.5 A (from AutoMax backplane) |
| Auxiliary Power | +12 V DC @ 53 mA, -12 V DC @ 7.5 mA |
| Rack Interface | P1/P2 female card slots on AutoMax backplane |
| Status Indication | 7-segment LED fault code + green OK status light |
| Mechanical Form | Single-slot AutoMax rack plug-in PCB assembly |
| Dimensions (L×W×H) | 229 × 51 × 152 mm (approx.) |
| Weight | 1.4 kg (approx.) |
| Coating | Conformal coating for industrial environments |
| Operating Temperature | 0°C to +60°C |
| Mounting | AutoMax/DCS 5000 rack backplane, tool-free ejector tabs |
| Revision | “C” revision with updated firmware |
| Product Status | Discontinued (EOL), available via spare parts channel |
