Siemens 6ES7 231-0HC22-0XA0 Analog Input Module

The Siemens EM 231 analog input module for the SIMATIC S7-200 family adds four analog input channels to a S7-200 CPU, accepting 0–10 V DC signals and converting them to 12‑bit digital values. Identified by order number 6ES7 231-0HC22-0XA0, the module fits in a compact form factor (71.2 mm wide × 80 mm high × 62 mm deep) and weighs about 183 g with a dissipation of 2 W. It requires a +5 VDC and +24 VDC supply and is designed for use with S7-22X CPUs, enabling straightforward expansion of voltage-sensing capability for sensors, transducers, or test setups that output 0–10 V signals. The EM 231 provides four independent AI channels and uses a fixed, non-removable connector, aligning with the S7-200 ecosystem alongside EM 232 (analog outputs) and EM 235 (mixed input/output) modules. Typical use cases include process monitoring, laboratory instrumentation, and automation tasks where precise voltage measurements from 0 to 10 V are needed and digital values must be fed directly into the S7-200 CPU for control decisions.