Features 1.Power Supply: The output TTL level can be detected by single chip microcomputer. Power supply can be 3‑5V can also be connected to PLC24V level. 2.Easy Connecting: When connecting to the PLC input terminal, the COM terminal of the PLC is connected to the 24V input of the power supply, connected to the signal output OUT of this board, and the GND on the optocoupler board is connected to the negative pole of the power supply. 3.3 Way Design: The green 2P 5.0 terminal is connected to 220V voltage, and the 3P terminal is connected to the input of the single chip microcomputer. 4.Good Material: Adopting high quality PCB board, not easy to malfunction, has good durability for long term use. 5.Easy to Install: Light in weight and compact in size, the installation is very convenient to complete in minutes. Specification Item Type: Optocoupler Isolation Module Material: PCB Function: Can be used to detect the presence of 220V AC. Function: Detect whether there is 220V AC power, stable output high and low level (NPN output). 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 does not light up, and the optocoupler does not work. The output is pulled high by the resistor. Package List 1 x Optocoupler Isolation Module