Overview
The 6ES7431-1KF00-0AB0 is a Siemens SM 431 analog input module for the SIMATIC S7-400 system, providing 8 isolated analog inputs with 13-bit resolution across voltage, current, and resistance measuring ranges. It draws 1.8 W from the backplane bus and occupies a single slot width of 25 mm, fitting into the standard S7-400 rack.
Function & operation
Temperature error is specified at 0.02 %/K across most ranges, with a tighter ±0.007 % in impedance measuring ranges. The module does not include onboard diagnostics, so fault detection relies on the CPU or external monitoring.
Market & positioning
The SM 431 series sits in the S7-400 analog input family, offering a balance of channel count and resolution for medium-density applications. The 6ES7431-1KF00-0AB0 is specified when the application requires resistance measurement alongside standard voltage and current inputs, without the higher channel count or thermocouple capability of other SM 431 variants.