This diagram shows the parallel connection of primary and secondary, with the output terminals connected in parallel and the RS485 interface of the primary and secondary connected in a straight line. When connecting in parallel, one is set as the primary and the others are secondary. If the customer needs to connect with PC, one can communicate through USB port, the program can control the primary, there is no need to control the secondary as the primary will automatically distribute the voltage and current, greatly simplifying the communication connection line and making it easier to use.