SIPLUS S7-300 SM 331 2AI 20-pin based on 6ES7331-7KB02-0AB0 with conformal coating, -25.+70°C, analog input electrically isolated 2 AI, resolution 9/12/14 bit, U/I/thermocouple/resistance, alarm, diagnostics, 1x 20-pin, pull/plug with active backplane bus Like the CPU, the analog input modules are also protected against extreme environmental conditions. Thanks to the 100% conformal coating, they can withstand biological, chemical and mechanically active substances, condensation, frost and harmful gases. No matter what the conditions - your analog signals are reliably recorded.