Omron 57C Series Modules: 57C404B, 57C424

Technical Dossier

Product Details And Specifications

Omron 57C Series: Comprehensive Module Range and Technical Overview

The Omron 57C Series represents a foundational I/O and control module family developed for the C200H and C500 programmable controller platforms. These modules have been deployed extensively across global heavy industry sectors including petrochemical refineries, nuclear auxiliary systems, pulp and paper processing, and continuous-process chemical plants. Their 5-slot and 10-slot backplane architecture, combined with a standardized bus interface, made the 57C Series a default specification in plant-wide DCS integration projects throughout the 1990s and early 2000s. Installed base counts in the tens of thousands of units remain active in facilities where full system migration is cost-prohibitive, making reliable spare parts sourcing a critical operational requirement.

The Evolution of 57C Series Architecture

The 57C Series was introduced as part of Omron's second-generation C-series PLC expansion I/O lineup, designed to interface directly with C200H and C500 CPU racks via a parallel backplane bus. Early modules in the range used discrete optocoupler isolation on digital I/O channels and 12-bit DAC/ADC conversion on analog variants. The 57C404B and 57C424 analog output units operate on a 4–20 mA or 0–10 V DC signal range, with 12-bit resolution and a maximum of 4 output channels per module slot.

As Omron transitioned its PLC portfolio toward the CJ1, CJ2, and NX Series platforms through the 2000s and 2010s, the 57C Series entered a formal end-of-life phase. Omron ceased new production of most 57C modules by approximately 2010–2012. However, the installed base in legacy plant environments has sustained a secondary market for tested, refurbished, and new-old-stock (NOS) units. Compatibility between 57C modules and C200H racks is governed by slot addressing and bus voltage specifications; cross-series substitution requires engineering validation and is not plug-compatible with CJ or NX backplanes without an adapter interface.

57C Series Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly sourced modules within the Omron 57C Series. Each entry reflects a distinct functional classification within the C200H/C500 I/O expansion architecture.

Analog Output Modules

• 57C404B: 4-channel analog output unit, 4–20 mA / 0–10 V, 12-bit resolution, C200H rack-mount
• 57C424: 4-channel analog output unit, voltage/current selectable output, C500 compatible backplane variant
• 57C414: 2-channel high-resolution analog output, 13-bit DAC, isolated signal conditioning
• 57C434: 8-channel analog output expansion unit, multiplexed DAC architecture, 4–20 mA

Analog Input Modules

• 57C304B: 4-channel analog input unit, 0–10 V / 4–20 mA, 12-bit ADC, C200H compatible
• 57C314: 4-channel analog input, thermocouple/RTD input capable, cold junction compensation
• 57C324: 8-channel analog input multiplexer unit, single ADC shared-channel architecture
• 57C334: High-speed analog input, 12-bit, 1 ms conversion time per channel

Digital Output Modules

• 57C104B: 16-point transistor output module, NPN sink type, 24 VDC, 0.5 A per point
• 57C114: 16-point relay output module, 250 VAC / 2 A per contact, C200H rack
• 57C124: 32-point transistor output, high-density I/O, NPN, 24 VDC
• 57C134: 8-point triac output module, 100–240 VAC, zero-cross switching

Digital Input Modules

• 57C204B: 16-point DC input module, 24 VDC, NPN/PNP selectable, C200H
• 57C214: 32-point DC input, high-density, 24 VDC, common bus architecture
• 57C224: 16-point AC input module, 100–240 VAC, optocoupler isolated

Communication & Special Function Modules

• 57C504B: DeviceNet communication adapter for C200H rack, master/slave configurable
• 57C514: RS-232C / RS-422 serial communication unit, protocol-configurable
• 57C524: SYSMAC LINK network module, coaxial bus, C200H host link compatible

Sourcing Hard-to-Find & Obsolete 57C Series Parts

The 57C Series has been formally discontinued by Omron. Standard distribution channels no longer carry new stock for the majority of models listed above. DriveKNMS maintains a dedicated inventory program for legacy Omron C-series modules, sourcing units through certified secondary market channels, decommissioned plant buybacks, and long-term storage NOS suppliers.

Quality Control for the 57C Series Range

All 57C Series modules processed by DriveKNMS undergo a structured functional test protocol prior to shipment. For analog output units including the 57C404B and 57C424, the test sequence includes: backplane bus continuity verification, DAC linearity sweep across the full output range (0–10 V and 4–20 mA), channel isolation resistance measurement, and loop-back signal accuracy validation at 0%, 25%, 50%, 75%, and 100% of rated output. Digital I/O modules are tested under simulated rack load conditions with point-by-point switching verification. Communication modules are validated against a reference C200H CPU for bus handshake and data integrity. Each unit is assigned a test record traceable to its serial number.