| ZRN-WLD Dewpoint Transmitter Through standard RS232 or RS422 / 485 communication port can be directly connected to computer communications: Communication protocol (standard MODBUS-RTU communication protocol): Using the standard MODBUS communication protocol when using the configuration software, are required to use the equipment for MODICON (Modicon) of the PLC, MODBUS-RTU address type data to an integer 16. Supports MODBUS protocol 03H, 04H, 06H instruction ( 03H, 06H read and write parameters, 04H read the measured value), Parameter Register Address: | parameter | Settings | Factory default Recognize the value of | communication instruction | Register address | | Temperature measurements | / | / | 04H | 00H | | Humidity measurements | / | / | 04H | 01H | | Dew point temperature value | / | / | 04H | 03H | | Native address | 0-255 | 1 | 03H, 06H | 00H | | Baud rate | 300-19200 | 9600 | 03H, 06H | 01H | | Temperature corrected translation | -99.9-100.0 | 0.0 | 03H, 06H | 02H | | Humidity correction translation | -99.9-100.0 | 0.0 | 03H, 06H | 03H | Example 1: read the temperature measured value (measured value = 1000) Send data: 01 04 00 00 00 01 31 CA Among them, 01 are native address, 04 is communication instruction, 0000 is starting to register Address 0001 represents read a number, 31 CA is a checksum. Returns data: 01 04 02 03 E8 B9 8E (which corresponds to 03 E8 measured value) Among them, 01 are native address, 04 is communication instruction, 02 returned values of bytes of data that is measured, B9 83 to test the code. Example 2: Read parameter value the machine address (local address = 1) Send data: 01 03 00 00 00 01 84 0A Among them, 01 are native address, 03 is communication instruction, 0000 is the starting address register, 0001 represents read a number, 84 0A is the checksum. Returns data: 01030200017984 Among them, 01 are native address, 03 is communication instruction, 02 returned values of bytes of data that is the address of the machine, the 7984 is a check code. Example 3: Write parameter value of the machine address (local address = 1, write a value of 2) Send data: 01 06 00 00 00 02 08 0B Among them, 01 when the machine address, 06 is communication instruction. 0000 is a register address 0002 indicates the parameter value. 08 0B is the checksum. Return data and send the data is consistent. |