The use of Asia Control Technology Kingview combined with Ebyte E90 series digital radio to realize remote acquisition and control PLC. The construction of the communication environment is mainly introduced here, so the overly complicated control program is not used, but in order to reflect the control effect, we use the most familiar lighting system as the test project, and introduce a holding register to test the working condition of the MODBUS 03 function code.

The configuration network uses Modicon's MODBUS RTU interface protocol to connect the E90 digital radio through the RS485 serial port, and use it as a host. The serial port No. 2 of Gumei CX3G-PLC (hereinafter referred to as PLC) is used as a MODBUS RTU slave to process the query and control commands of Kingview.

Use the seventh discrete input port (X06) of the PLC as the local control point for turning on the light, use the eighth discrete input port (X07) as the local control point for turning off the light, and use M2 as the remote control point for turning on the light. point, use M3 as the remote control point of Kingview lights off.
Use the second register (D8013) of the PLC special register to automatically assign value to the Kingview read register (D0).

There is generally a long distance between the central control room and the PLC control cabinet. The use of digital radio can reduce the time cost and construction cost of wiring and later fault inquiry, and also facilitate later function expansion. In addition, it has the following advantages.
1. It can solve the problem of long wiring construction period or even impossible to implement in environments that are difficult to wire (mountains, ports and open areas, etc.).
2. The distribution network is convenient and flexible, with good scalability. Device configuration can be achieved with little time cost.
3. Maintenance and fault inquiry are convenient and quick.
4. Multi-point control can be easily realized.
5. All RTU devices can be expanded in this way.