Modbus RTU temperature and humidity sensor description:
1. The sensor adopts an integrated design with a built-in temperature and humidity measuring element, and the overall appearance is small and exquisite, which is suitable for installation in a small place to measure temperature and humidity.
2. The Modbus RTU temperature humidity sensor has pluggable wiring terminals, easy to install, and easy to maintain during use.
3. High-quality measurement unit imported from Switzerland, accurate measurement.
4. 10~30V wide voltage range power supply, complete specifications.
RS485 modbus temperature humidity sensor specifications:
Power supply (default): 10-30V DC
Power consumption: 0.3W
Humidity: ±2%RH (5%~95%RH, 25℃), temperature: ±0.4℃ (25℃)
(Default) Humidity: ±3%RH (5%RH~95%RH, 25°C), temperature: ±0.5°C (25°C)
Transmitter circuit working temperature: -40℃~+60℃, 0%RH~80%RH
Communication protocol: Modbus-RTU communication protocol
Output signal: 485 signal
Temperature display resolution: 0.1℃
Humidity display resolution: 0.1%RH
Temperature and humidity refresh time: 1S
Long-term stability: temperature ≤0.1℃/y humidity ≤1%RH/y
Response time: Temperature ≤15s (1m/s wind speed) Humidity ≤4s (1m/s wind speed)
Parameter setting: through software setting
Other related temperature sensors:
The communication protocol of the RS485 temperature humidity sensor:
1. Basic communication parameters:
|Stop bit||1 bit|
|Error checking||CRC (Redundant Cyclic Code)|
|Baud rate||2400bit/s, 4800bit/s, 9600 bit/s can be set, the factory default is 4800bit/s|
2. Data frame format definition
Using Modbus-RTU communication protocol, the format is as follows:
Initial structure ≥ 4 bytes of time
Address code = 1 byte
Function code = 1 byte
Data area = N bytes
Error check = 16-bit CRC code
Time to end structure ≥ 4 bytes
Address code: the address of the transmitter, which is unique in the communication network (factory default 0x01).
Function code: The command function instruction issued by the host, this transmitter only uses function code 0x03 (read register data).
Data area: The data area is the specific communication data, pay attention to the high byte of the 16bits data first!
CRC code: two-byte check code.
Host query frame structure:
|address code||function code||Register start address||Register length||Check code low bit||The high bit of check code|
|1 byte||1 byte||2 bytes||2 bytes||1 byte||1 byte|
Slave machine response frame structure:
|address code||function code||Number of valid bytes||Data area||Second data area||Nth data area||Check code|
|1 byte||1 byte||1 byte||2 bytes||2 bytes||2 bytes||2 bytes|
3. Register address
|Register address||PLC or configuration address||Content||Operating|
4. Communication protocol example and explanation
Example: Read the temperature and humidity value of the device address 0x01
Inquiry frame (hexadecimal):
|Address code||Function code||Starting address||Data length||Check code low bit||The high bit of check code|
|0x01||0x03||0x00 0x00||0x00 0x02||0xC4||0x0B|
Response frame (hexadecimal): (for example, the temperature is -10.1℃ and the humidity is 65.8%RH)
|Address code||Function code||Returns the number of valid bytes||Humidity value||Temperature value||Check code low bit||The high bit of check code|
|0x01||0x03||0x04||0x02 0x92||0xFF 0x9B||0x5A||0x3D|
When the temperature is lower than 0 ℃, the temperature data will be uploaded in the form of complement code.
Temperature: FF9B H (hexadecimal) = -101 => temperature = -10.1℃
Humidity: 292 H (hexadecimal) = 658 => Humidity = 65.8%RH
RS485 modbus rtu temp and humidity sensor application:
RS485 Modbus RTU temperature and humidity sensor is a card rail type 485 output temperature and humidity transmitter are widely used in communication rooms, warehouse buildings, and automatic control, and other places that require temperature and humidity monitoring. The input power of the sensor, the temperature measurement unit, and the signal output is completely isolated. It is safe and reliable, beautiful in appearance, and easy to install. 485 communication interface standard Modbus-RTU communication protocol, communication address, and baud rate can be set, the communication distance is up to 2000 meters.
Q: Where to download the rs485 modbus temperature humidity sensor manual?
A: To protect the patented technical parameters, please contact us for a manual.
Q: Do you support after-sales service?
A: Support, our products provide a two-year warranty, and there are dedicated technical personnel who can solve various technical problems for you through online contact.
Q: The reason why the modbus temperature sensor cannot connect to the PLC or computer?
A: 1. The computer has multiple COM ports, and the selected port is incorrect.
2. The device address is wrong, or there are devices with duplicate addresses (the factory default is all 1).
3. The baud rate, check method, data bit and stop bit are wrong.
4. The host polling interval and waiting response time are too short, and both need to be set above 200ms.
5. The 485 bus is disconnected, or the A and B wires are connected reversely.
6. If the number of equipment is too much or the wiring is too long, the power supply should be nearby, add 485 boosters, and add 120Ω terminal resistance at the same time.
7. The USB to 485 drivers is not installed or damaged.
8. The equipment is damaged.
Q: Do you have this modbus temperature sensor video?
A: Yes, please check our temperature and humidity sensor video.
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