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

Siemens EM 231 Analog Input module (order number 6ES7 231-0HC22-0XA0) adds four 0-10 V analog inputs to SIMATIC S7-22X CPUs, converting sensor signals to digital data with 12‑bit resolution. Designed specifically for the S7-22X family, the EM 231 plugs into the CPU’s I/O area to expand input capability without reconfiguring the controller. Each channel accepts 0–10 V DC signals, enabling direct interface to common process sensors and transducers, while providing four independent conversions fed into the S7-22X. The module measures 71.2 mm wide by 80 mm high by 62 mm deep, weighs about 183 g, and dissipates roughly 2 W, making it suitable for DIN-rail mounting in standard control panels. It requires the PLC’s supply rails: +5 V DC for logic and +24 V DC for field power. The EM 231 delivers isolation between field signals and the logic domain to support reliable data acquisition in industrial environments, and facilitates accurate monitoring of analog process variables such as temperature, pressure, and level in automation systems that use the S7-22X line.