Reliance Electric 57C410A Analog Output Module

Technical Dossier

Product Details And Specifications

Reliance Electric 57C Series Technical Notes

The Evolution of 57C Architecture

The 57C Series was introduced as part of Reliance Electric's second-generation modular control platform, succeeding earlier discrete relay-based systems. Its backplane architecture uses a parallel bus structure that supports synchronous data exchange between the CPU module and up to 16 I/O slots per rack. Early revisions of the 57C platform used EPROM-based firmware stored on socketed ICs, which allowed field firmware updates without module replacement — a significant serviceability advantage for remote installations. As Rockwell Automation acquired Reliance Electric in 1995, the 57C Series entered a managed lifecycle phase. Firmware revisions were frozen, and the platform was positioned as a legacy system alongside Rockwell's Allen-Bradley ControlLogix and PLC-5 families. Compatibility between 57C racks and AutoMax supervisory software versions 3.x through 6.x has been documented, though integration with modern OPC-UA or EtherNet/IP networks requires third-party protocol converters. Sites migrating away from 57C hardware typically transition to Allen-Bradley ControlLogix 1756 or Rockwell's PlantPAx DCS, though the capital cost and process risk of full migration sustains demand for original 57C spare parts well into the 2020s.

57C Series Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly sourced modules within the Reliance Electric 57C Series. Modules are classified by functional category.

Analog Output (AO) Modules

• 57C410A: 4-channel analog output module, 4–20 mA / 0–10 V DC, 12-bit resolution, rack-mount
• 57C411A: 8-channel analog output module, 4–20 mA current loop output, isolated channels
• 57C412A: 4-channel high-resolution analog output, 16-bit DAC, voltage/current selectable

Analog Input (AI) Modules

• 57C401A: 8-channel analog input module, 4–20 mA, 12-bit ADC, single-ended
• 57C402A: 8-channel differential analog input, thermocouple/RTD compatible, 14-bit resolution
• 57C403A: 16-channel analog input multiplexer module, 4–20 mA, rack-mount
• 57C404A: 4-channel high-speed analog input, 16-bit ADC, 1 kHz sample rate per channel

Digital Input (DI) Modules

• 57C421A: 16-channel 24 V DC digital input module, sourcing, optically isolated
• 57C422A: 32-channel 24 V DC digital input module, sinking/sourcing selectable
• 57C423A: 16-channel 120 V AC digital input module, optically isolated, DIN-rail compatible

Digital Output (DO) Modules

• 57C431A: 16-channel 24 V DC digital output module, sourcing, 0.5 A per channel
• 57C432A: 16-channel relay output module, Form C contacts, 2 A per channel at 120 V AC
• 57C433A: 32-channel 24 V DC digital output module, sinking, short-circuit protected

CPU / Controller Modules

• 57C300A: AutoMax rack controller module, 80186 processor, 256 KB RAM, AutoMax OS compatible
• 57C301A: Enhanced rack controller, 80386 processor, 1 MB RAM, supports multi-rack expansion

Power Supply Modules

• 57C100A: 5 V DC rack power supply module, 10 A output, 120/240 V AC input, internal fan-cooled
• 57C101A: Redundant power supply module, hot-swap capable, for critical process applications

Communication / Adapter Modules

• 57C350A: AutoMax network adapter module, coaxial bus interface, peer-to-peer communication
• 57C351A: Remote I/O adapter module, supports up to 4 remote rack drops, RS-485 physical layer