Features:
Function: Test whether AC 220V is existed
Output TTL Level: can use MCU to test,voltage is 3-5V
Output can connect PLC 24V

Wiring:
When connecting the PLC input, the PLC's COM terminal is connected to the 24V power supply, the input is connected to signal outputs S1-S8 of the board, optocoupler GND is connected to the power supply negative.
Blue 5.0 terminal is connected to 220V voltage, yellow pin signal output.
When the 220V voltage is normal, it output low level; when 220V is powered off, it output high level.

Note:
Do not touch any part of the white wire frame on the board after the module is powered on, because it is high voltage. Pay attention to electricity safety.