RS485 3in1 Light intensity Sensor Modbus Protocol Temperature and Humidity Transmitter Sensor

Specification
DC power supply:10-30VDC
Maximum power consumption:0.4W
Accuracy
Humidity:± 3% RH (5% RH ~ 95% RH, 25C)
Temperature:± 0.5C, (25C)
Light intensity:± 7% (25C)
Light intensity range:0-65535lux
Working temperature:-20 ~ 60C, 0% RH ~ 80% RH
Long-term stability
Temperature:0.1C / y
Humidity:1% / y
Light intensity:5% / y
Response time
Temperature:18S (1m / s wind speed)
Humidity:6s (1m / s wind speed)
Light intensity:0.1S
Output signal:RS485 output (Modbus protocol):Cable color:instruction
Power:Brown:10~30V DC power +
Black:Power –
communication:yellow:485-A
blue:485-b
The default baud rate is 4800bit/s, and the default address is 0x01.
1. communication protocol
Code:8 bit binary system
Data bits:8bits
parity check bit:NO
stop bit:NO
Error checking:CRC
baud rate:2400bit/s4800bit/s9600 bit/s 4800bits by default
2. Using Modbus-RTU communication protocol, the format is as follows
The initial structure is more than 4 bytes of time
Address code = 1 bytes
Function = 1 bytes
Data area = N bytes
Error check = 16 bit CRC code
The end of the structure is greater than or equal to 4 bytes of time
Address code:the address of the transmitter, which is unique in the communication network (factory default 0x01).
Function code:the instruction function instruction from the host. The transmitter only uses the function code 0x03 (read register data).
Data area:data area is specific communication data, pay attention to 16bits data before the high byte!
CRC Code:two byte check code
Host query frame structure
Address code:Function code:Register start address:Register length:check code low:Check code high
1 bytes:1 bytes:2 bytes:2 bytes:1 bytes:1 bytes
Slave transponder frame structure
Address code:Function code:effective byte:No 1 Data area:NO2 Data area:No N Data area:Check code
1 bytes:1 bytes:1 bytes:2 bytes:2 bytes:2 bytes:2 bytes
3.Register address
Register address:PLC or configuration address:content:operation
0000 H:40001:humidity:read-only
0001 H:40002:temperature:read-only
0002 H:40003:Illuminance 0~200000Lux use unit 1Lux:read-only
0003 H:40004
0006 H:40007:Illuminance 0~65535 unit 1 Lux ,0~200000 unit 100Lux:read-only
4.Examples and explanations of communication protocols
4.1Read the temperature and humidity values of the device address 0x01
Query frame
Address code:Function code:Start address:Data length:check code low:Check code high
0x01:0x03:0x00 0x00:0x00 0x02:0xC4:0x0B
Response frames (for example, read the temperature of -10.1 degrees C and humidity of 65.8%RH)
Address code:Function code:effective byte:humidity:temperature:check code low:Check code high
0x01:0x03:0x04:0x02 0x92:0xFF 0x9B:0x5A:0x3D
.Temperature:when the temperature is below 0 degrees, it is uploaded in the form of complement
FF9B H (Hexadecimal) = -101 = -10.1 = > temperature c
Humidity
292 H (Hexadecimal) =658=> humidity = 65.8%RH
4.2 Read the illumination value of the device address 0x01
(0~65535 reads in 1Lux or 0~200000 reads in a hundred Lux units)
Query frame
Address code:Function code:Start address:Data length:check code low:Check code high
0x01:0x03:0x00 0x06:0x00 0x01:0x64:0x0B
Response frames (for example, read illumination is 200000 Lux)
Address code:Function code:Returns the number of valid bytes:Data area:check code low:Check code high
0x01:0x03:0x02:0x05 0x30:0xBB:0x00
Illumination calculation description
1) the product is 0~65535 range transmitter, the unit is 1Lux
0530 H (sixteen hex) = 1328=> illuminance =1328 Lux
2) the product is 0~200000 range transmitter, the unit is 100 Lux
0530 H (sixteen hex) = 1328=> illuminance =132800 Lux
4.3 Read the illumination value of the device address 0x01 (0~200000 is read as 1Lux)
Query frame
Address code:Function code:Start address:Data length:check code low:Check code high
0x01:0x03:0x00 0x02:0x00 0x02:0x65:0xCB
Response frames (for example, read illumination is 200000 Lux)
Address code:Function code:Significant bytes:High light intensity:low light intensity:check code low:Check code high
0x01:0x03:0x04:0x00 0x03:0x0D 0x40:0x0F:0x53
Illumination calculation description
This protocol is only used under the 0~200000Lux range transmitter, 1Lux
30D40, H (sixteen hex) = 200000=>, illuminance =200000, Lux
4.4 Read the temperature, humidity, and illumination values of the address 0x01 of the device
(0~65535 reads in 1Lux or 0~200000 reads in a hundred Lux units)
Query frame
Address code:Function code:Start address:Data length:check code low:Check code high
0x01:0x03:0x00 0x00:0x00 0x07:0x04:0x08
Response frames
Address code:Function code:Bytes:humidty:temperature:**:Illuminance:Check code
0x01:0x03:0x0E:0x02 0x92:0x80 0x65:00 Fill:0x05 0x30:0xC4 0x33
4.5 Read the temperature, humidity, and illumination values of the address 0x01 of the device
(0~200000 reads in 100 Lux units)
Address code:Function code:Start address:Data length:check code low:Check code high
0x01:0x03:0x00 0x00:0x00 0x04:0x44:0x09
Response frames
Address code:Function code:Bytes:humidty:temperature:Illuminance high:Illuminance low:Check code
0x01:0x03:0x03 0x08:0x02 0x92:0x80 0x65:0x00 0x03:0x0D 0x40:0x01 0x6F
5. The device cannot connect to PLC or computer
Possible causes
1) the computer has multiple COM ports, and the choice is incorrect.
2) device address error, or the existence of repeated address devices (factory default all 1).
3) baud rate, check mode, data bits, stop bit error.
4) The 485 bus is disconnected, or the A and B lines are reversed.
5) If the number of devices is too large or the wiring is too long, the power should be supplied nearby, add 485 booster, and increase the resistance of 120 terminal.
6) The USB to 485 driver is not installed or damaged.
7) Equipment damage.
Package includes
1xTemperature and Humidity Transmitter Sensor
Details Pictures: