User Manual

Table Of Contents

User Manual

Page 30 of 45

① Measurement ID: The unique ID of the sensor's custom measured value, the value is an integer, and the

range is [5500, 5999] and [4097, 4099]. For example, set the ID of the measured value of soil temperature

to 5500, that is, 5500 represents the value of soil temperature.

② Function Code: Modbus function code, supports 03 and 04 function code.

③ Register Address: The register address of the measured value in the sensor, which is an integer. For example,

the soil temperature value register address is 0.

④ Data type: The data type determines the number of registers read from the sensor and how the data should

parse the value. If the soil temperature and moisture is INT16, select "signed 16bit integer,0xAB".

⑤ Precision: The number of places of the acquisition value, affecting only the numeric output format,

independent of parsing.

⑥ Factor A: The data will be parsed in the format of formula Ax + B, with both A and B as coefficients for

single-precision floating points and x as measurements. If the value read from the temperature register is

2555, the actual value is 2555/100. A is set to 0.01, B is set to 0, and the actual value is (0.01, 25 55 ,0)

according to formula A*x + B, the actual value is 0.01*2555+0 = 25.55 °C

⑦ Factor B: The data will be parsed in the format of formula A*x + B, with a single-precision floating point.

⑧ Write Strategy: Special types, such as rainfall, need to be written at a specific point in time: after reading

zero or after the date changes (CST 00:00 per day).

⑨ Command in Hex: Once the writing strategy is determined, fill in the write command that needs to be

executed, which is Modbus' HEX command string, which is "function code + data", for example,

"06 00 00 00 00", the maximum support for command A is 10 bytes.

Following the above method, add a soil moisture value and set the measurement ID to 5501: