SG72 module is a communication port conversion module of USBcontrol or move some details on the generators,<->RS232, ... , this light will flash.3, POWER LED: When the SG72 module successfully connect to USB, this light will be illuminated.4 ... .6, RS485: This is a generic isolation RS485 communication interface.7, RS232-C: This is a generic DB9 serial communication interface. SG72 Communication module