Specifications Main Range of produc Modicon M171 Product or component type Controller Complementary Number of port 1 Modbus serial link - RS485 Input/output number 8 total) 4 analog input 2 digital input 2 digital output Discrete input number 2 Discrete input logic Sink or source (positive/negative) contacts usage Volt-free contacts Sensor power supply 5 V DC 12 V DC Discrete output number 1 open collector 1 SPST Analogue input number 2 analog input NTC 2 analog input Pt 1000 4...20 mA or 0...5 V or 0...10 V [Us] rated supply voltage 24 V +/- 10 % AC/DC Display type Without display mounting support DIN rail Width 2.76 in (70.2 mm) height 3.43 in (87 mm) Depth 2.43 in (61.6 mm) Environment Marking CE Ambient air temperature for operation 23…122 °F (-5…50 °C) IP degree of protection IP20