Item Type: Opto Isolator Module_x000D_Material: PCB_x000D_Function: Can be used to detect the existence of 220V AC_x000D_Function: Detect whether there is 220V AC power, stable output high and low level (NPN output)_x000D_When there is 220V input, the LED is on, the optocoupler is turned on and the output is low_x000D_When there is no 220V input, the LED does not light up, and the optocoupler does not work. The output is pulled high by the resistor 1DETECT OUTPUT TTL LEVEL: The output TTL level can be detected by a microcontroller, power supply can be 3?5V, can also be connected to PLC 24V level 2PLC TERMINAL: When connecting to the PLC input terminal, the COM terminal of the PLC is connected to the 24V input terminal of the power supply, connect the signal output OUT of the board, and the GND on the optocoupler board is connected to the negative pole of the power supply 3WITH 2P AND 3P TERMINAL: The green 2P 5.0 terminal is connected to 220V voltage, and the 3P terminal is connected to the input of the microcontroller 4STABLE HIGH LOW LEVELS OUTPUT: Can be used to detect the existence of 220V AC power, and stably output high and low levels (NPN output) 5LED LIGHT INDICATOR: When there is 220V input, the LED is on, the optocoupler is turned on and the output is low. When there is no 220V input, the LED is off, the optocoupler is not connected. The output is pulled high by the resistor1 x Opto Isolator ModuleWhen the module is used, should be placed in a dry and ventilated environment with good insulation protection.