3 Channel 220V optocoupler isolation module, using NPN transistor to output saturated conduction current up to 100-300MA; The module can be used to detect the presence of 220V AC power; When there is 220V, the coupling conduction output is low level; When there is no 220V, Output is a stable high and low level; It can be directly connected to the IO port of the microcontroller for detection, or it can be connected to a PLC compatible with all PLC inputs