Temperature & Humidity Transmitter SHT20 Sensor High Precision Monitoring Modbus RS485 RTU PLC system integration
Product Introduction:
The product adopts industrial grade chip, high-precision imported SHT20 temperature and humidity sensor to ensure the excellent reliability, high precision and interchangeability of the product. Using RS485 hardware interface (with lightning protection design), the protocol layer is compatible with standard industrial Modbus-Rtu protocol. This product integrates the MODBUS protocol and the common protocol. The user can choose the communication protocol. The common protocol has an automatic upload function (connecting RS485 through the serial port adjustment tool will automatically output temperature and humidity).
Product parameters: Product name: temperature and humidity transmitter DC power supply: DC 5V-30V Output signal: RS485 signal Temperature accuracy: ±0.5℃ (25℃) Humidity accuracy: ±3%RH Temperature range: 0%RH-80%RJ Temperature resolution: 0.1℃ Humidity resolution: 0.1%RH Equipment power consumption: ≤0.2W Communication address: 1-247 can be set, default 1 Communication protocol: Modbus-RTU protocol and custom common protocol Baud rate: configurable, default 9600, 8-bit data, 1-bit stop, no parity Wiring: Modbus protocol:0x03:Read keep register
0x04: Read input register
0x06:Write a single keep register
0x10:Write more keep registers
Master send format:
The responseformat of slave:
The response data from slave:
Temperature value=0x131,converted to a decimal 305,the actual temperature value = 305 / 10 = 30.5°
Note: the temperature is signed hexadecimal number, temperature value = 0xFF33, converted to a decimal - 205, the actual temperature = -20.5 °;
The response data from slave:
Humidity value = 0x222, converted to a decimal 546, actual humidity value = 546/10 = 54.6 %;
The response data from slave:
Readdevice address from the slave:
The response data from slave:
Modify the slave address register:
Modify the slave address:0x08 = 8
The response data from slave(And send the same):
Slave address :0x20 = 32
Baud rate :0x2580 = 9600
The response data from slave:
The default baud rates9600 (the user can set), 8 bits of data, one stop, no check
RS485
CMD | instructions |
READ | Report triggered a temperature and humidity (27.4°,67.7% 温度27.4°湿度67.7%) |
AUTO | Start the temperature and humidity automatically report function(Same as above) |
STOP | Stop the temperature and humidity automatically report function |
BR:XXXX | Set the baud rate 9600~19200 (BR:9600) |
TC:XX.X | Set the temperature calibration(-10.0~10.0) (TC:02.0温度修正值为2.0°) |
HC:XX.X | Set the humidityration(-10.0~10.0) (HC:-05.1 湿度修正值为 -5.1%) |
HZ:XXX | Set the temperature and humidity reporting rate(0.5,1,2,5,10) (HZ:2 reporting rate 2Hz) |
PARAM | Read the system current Settings |
PARAM CMD:
TC:0.0,HC:0.0,BR:9600,HZ:1 ->Temp calibration 0.0, Humi calibration0.0, Baud rate 9600,report rate 1Hz
SLAVE_ADD:1 ->MODBU Slave address 1