Due to the shortdistance of the traditional industrial wired RS485 wiring, and the small numberof RS485 communication equipment mounted on the bus can not meet the needs ofthe current intelligent industrial site. And wired RS485 communication hasstrict requirements for complicated wiring and cumbersome requirements in theindustrial field, high requirements for communication line quality, unstablelong-distance communication, and difficulty in troubleshooting.

Wireless digital radio (DTU) refers to the realization of high-performanceprofessional data transmission stations by means of single-chip technology andradio technology, which can transmit services including remote telemetry data,digitized voice, and dynamic images. The application of the wireless datatransmission radio has the advantages of long communication distance, stablecommunication, and no need for complicated wiring. In the communicationinterface, the wireless data transmission station (DTU) satisfies variouscommunication requirements such as RS485/RS232.
The ebyteE90-DTU used in this application realizes stable performance, hightransmission efficiency, long communication distance and many kinds of communicationinterfaces.

Performanceparameters:
Carrier frequency: 433/230/170MHz
Transmit power: 27/30/33/37dBm
Communication distance: 5/8/10/15/20km
Interface type: RS232/RS485
The following application of E90-DTU in environmental intelligence monitoringand agricultural control is an example to illustrate how the use of DTU in theindustry can replace traditional wired RS485 wiring.

It can be seenfrom Fig. 1 that the meteorological monitoring equipment, air pollutionmonitoring equipment, agricultural sprinkler equipment, etc. can be connectedto the radio through RS485/RS232, and then the radio station transmits to thereceiving end through wireless transmission, and the receiving station passesthe Modbus protocol. Transfer multiple data to the data center for dataprocessing and analysis. It can be seen that the wireless communication usingDTU replaces the traditional RS485 wiring, so that no complicated communicationwiring is needed in the industrial field, and the communication debugging of theradio station is simpler and more convenient than the traditional RS485communication debugging.

In the agricultural sprinkler system, the Zigbee module can also be used torealize the intelligent connection and networking between the devices, and thenthe router is connected with the radio to realize communication and control ofthe industrial site.