At present, many industrial control devices use the RS-232 interface mode, and most barcode scanners can be equipped with an RS-232 cable. The schematic diagram of the connection with the device is shown in the figure below.

Its installation method is as follows:

1. Turn off the power of the device.

2. Connect one end of the crystal plug of the connecting line to the end of the scanner gun.

3. Connect the other end to the 9-pin serial interface of the device.

4. If the device (pin 9 of the serial interface) does not provide power, connect an external 5V power supply to the connection cable.