Industrial 57409-C Isolated Control Analog Input Module

The Reliance Electric 57409-C Isolated Control Analog Input Module is a two-channel analog input device designed for Reliance Electric AutoMax PLC systems. It provides galvanic isolation between the input signals and the logic backplane, with up to 600 V isolation to the logic common, and it powers the isolated section from an on‑board DC‑DC converter that supplies isolated rails of +15 V and -15 V while sharing a single isolated common for both channels. Each channel accepts an analog signal and feeds a digital input path through the module’s isolated circuitry, enabling safe measurement of external voltages or signals without compromising the main control circuitry. Conversion rate is described as fast as 500 microseconds per conversion, supporting responsive monitoring and control. The faceplate includes four LEDs that reflect the module’s clock status and testing state: the top LED indicates whether a common clock is present, the next LED shows if the module is driving the common clock, and the remaining two LEDs serve factory test indications. This module is a two-channel A/D input option within the AutoMax peripheral family, typically installed in the adjacent rack position to bring external analog signals into the PLC. Its historical catalog reference is 0-57409-C (also seen as 57409-C), aligning with Reliance Electric’s legacy 57C4xx/57C409 family of isolated analog inputs.