The Modbus RTU device wirelessly replaces the wired device is to connect the RS485 interface of the Modbus master and slave to a wireless data transmission station with a 485 interface. The communication depends entirely on the wireless data transmission station for signal transmission and signal reception, getting rid of the trouble of 485 first, as long as it is within the communication range of the wireless data transmission station, the Modbus RTU master device and slave device can be moved to any position, not affected by the traditional RS485 Line constraints, greatly reduced equipment costs and wiring difficulties.

Since the communication between the Modbus RTU master and the slave needs to be forwarded wirelessly, the time is slower than that of the wired RS485, so the interval between the master and the slave needs to be longer.

Some wireless data transmission stations need data packetization. The data length of sending modbus commands or replying modbus commands should be smaller than the packet length of wireless data transmission stations. Otherwise, the data received by the host or slave will be out of frame. In this case, you can choose a wireless data transmission station with a longer packet or a wireless data transmission station without packetization. If conditions permit, the frame break time of the master and slave can also be adjusted.

If the communication frequency between the host and the slave is fast, the airspeed of the wireless data transmission station can be increased to allow the wireless data transmission station to transmit data faster, but this will sacrifice the transmission distance of some wireless data transmission stations.

Two devices with the same address are not allowed in the same Modbus RTU network, which will cause interference to the wireless signal and fail to receive data successfully.