Siemens 6ES7231-4HD32-0XB0 Analog Input Module

The Siemens 6ES7231-4HD32-0XB0 is a four-channel analog input module for the SIMATIC S7-1200 family (SM 1231) that accepts voltage signals in ±10 V, ±5 V, or ±2.5 V ranges, or current signals in 0-20 mA and 4-20 mA for all four channels. Each channel feeds a 13‑bit ADC (12‑bit value with a sign bit) to provide bipolar measurements, while input impedance for the voltage ranges is ≥9 MΩ and the current ranges present about 280 Ω of input resistance, enabling precise sensing of small signals with minimal loading. The module is powered from 24 V DC and plugs into the S7-1200 backplane as part of the SM 1231 analog input family, delivering a typical conversion time of 625 µs per channel to support real‑time monitoring and control; its four inputs are independently configurable to suit different sensors and signal types for applications such as sensor interfacing, process monitoring, and data acquisition in automation environments.