#04-2, M1S: Three Isolated Inputs, Common (–)
Function: Three optically isolated inputs with common (-). Inputs are fully isolated from system ground.
Form factor: M1S
Category: Input module
Special needs: ---
Power requirements: 5V/35mA
If no external resistor is added, these inputs activate at about 2V. Forward current should not exceed 10mA, which caps the maximum input voltage at about 5V. Add external resistors if you need to apply a higher input voltage.
There are three green LEDs connected to the three control lines. The LEDs light up for the LOW state of the control lines (i.e., when current passes through the diodes of the opto-couplers).