Siemens 6ES7231-0HC21-0XA0 Programmable Logic Controller Module

Siemens 6ES7231-0HC21-0XA0 is the EM231 analog input module for the SIMATIC S7-200 family, designed specifically for S7-22x CPUs. It provides four analog inputs that accept 0-10 V DC signals and convert them with a 12-bit resolution, enabling precise voltage measurements from sensors and transducers in automation tasks. The module's compact footprint measures about 60 mm in height, 70 mm in width, and 100 mm in length and weighs roughly 0.30 kg. This part is typically used to acquire process signals such as sensor voltages in industrial automation projects, interfacing directly with S7-200 CPUs to feed digital control logic and data logging systems. As a component of the SIMATIC S7-200 ecosystem, the EM231 is specified for use with S7-22x CPUs only, reinforcing its role in expanding the analog input capability of compatible PLC configurations. Typical applications include monitoring temperature or pressure sensors via 0-10 V outputs, data logging, and feeding control decisions in compact S7-200 automation projects.