SIMATIC S7-1200
Analog input, SM 1231, 4 AI, +/-10 V, +/-5 V, +/-2.5 V, or 0-20 mA/4-20 mA
12 bit+sign (13 bit ADC)
Number of analog inputs : 4; Current or voltage differential inputs
permissible input voltage for voltage input (destruction limit), max. :35 V
permissible input current for current input (destruction limit), max. : 40 mA
Cycle time (all channels) max. : 625 µs