Siemens 6ES7331-7NF10-0AB0 is an eight-channel analog input module (SM331) for the SIMATIC S7-300 family. The module is optically isolated and uses a single common reference (60 V COM) with a 40-pin backplane connector, enabling safe, multi-signal measurements in mixed- voltage environments. It accepts voltage inputs in ±5/10 V and 1–5 V ranges and current inputs in ±20 mA and 0–20 mA, all at 16-bit resolution with channel isolation. Sampling times are 10 ms in 4-channel mode and 23–95 ms in 8-channel mode; the module is designed for a 24 V DC supply and weighs about 0.33 kg.
