XLJH-Z Communication bus switches is a communication distributor developed by our company. When the field communication bus is far away from the RS-485 transmission distance, it can be used as a middle repeater to extend the communication distance. When the controlled device cannot be wired according to RS-485 bus specification in the project and is connected into a star branch structure, it can be used as a RS-485 bus distributor. This product is the RS-485 long-distance communication essential products!