Siemens 6ES7331-7KB01-0AB0 is an analog input module for the SIMATIC S7-300 family, specifically the SM 331, delivering two isolated analog input channels for reading sensor signals. It supports multiple input types—voltage (U), current (I), thermocouple, and resistance—and offers selectable resolutions of 9, 12, or 14 bits to balance speed and precision, with built-in alarm and diagnostics to monitor channel status. The module mounts in an S7-300 rack, uses a 1 × 20-pin connector, and is designed for easy removal/installation with an active backplane bus.
