Reliance Electric 45C46 Input Module Dual Voltage Comparator

The Reliance Electric 45C46 Dual Voltage Comparator Input Module is a voltage‑comparison I/O module designed for Reliance AutoMax/AutoMate PLC systems. It provides two input channels that monitor analog voltages and compare each to a user‑set reference, generating a binary decision (greater than or less than the reference) that the processor can act upon. The module supports external signals up to a maximum of 10 V DC per input, making it suitable for simple threshold‑based monitoring in automation circuits. Front‑panel controls include INCR Reference and INCR Dead Band, allowing precise thresholding and noise immunity through adjustable hysteresis. Two status LEDs, labeled ODD‑HI and EVEN‑HI, give immediate visual feedback of the comparator outcomes for quick diagnostics. The 45C46 mounts on the Reliance AutoMax I/O rail (in the 45C1 family) and interfaces via a backplane/slot arrangement typical of standalone voltage‑monitoring modules, with optical isolation characteristics common to Reliance I/O modules of the era. Functionally, the 45C46 determines whether an incoming analog voltage exceeds or falls below the preset reference, and conveys that result to the control processor for downstream logic. As part of the AutoMax voltage‑monitoring family, it complements other input options and is designed to integrate with the broader Reliance Electric control ecosystem, enabling threshold‑based control without requiring additional analog–to–digital processing steps within the central controller.