The smaller of the two devices has 10 digital inputs, 4 analog inputs, and 8 digital outputs able to sink 200 mA each. The larger PLC has 22 digital ins, 6 analog ins, and 16 digital outputs.

In the case of a programmable logic controller (PLC) digital output card, the card turns on an LED inside the card, which switches on the field current using a phototransistor. For a PLC digital input ...