Function 0X04 - Read Temperature And Humidity Value - Protech Systems SI-W309 User Manual

4.2.3 Function 0x04 – Read Temperature and Humidity Value
This function code is used to read the temperature and humidity sensor value of
SI-W309 I/O module.
Request
Offset Description
00 Slave ID address
01 Function Code
02 ~ 03 Channel address
04 ~ 05
Response-1
The channel address is 0x4640.
Offset Description
00 Slave ID address
01 Function Code
02 Byte Count
03 ~ 04 Readback value
05 ~ 06 CRC
Response-2
The channel address is 0x4650.
Offset Description
00 Slave ID address
01 Function Code
02 Byte Count
03 Readback value
04 ~ 05 CRC
Error Response
Offset Description
00 Slave ID address
01 Function Code
02
03 ~ 04
SI-W309 SERIES USER MANUAL
Counts
1 Byte
1 Byte
2 Bytes
CRC 2 Bytes
Counts
1 Byte
1 Byte
1 Byte
2 Bytes
2 Bytes
Counts
1 Byte
1 Byte
1 Byte
1 Bytes
2 Bytes
Counts
1 Byte
1 Byte
Data 1 Byte
CRC 2 Bytes
Chapter 4 MODBUS RTU Protocol
Data
1 to 255
0x04
•
0x4640: Get Temperature Value
•
0x4650: Get Humidity Value
Produced by utility.
Data
1 to 255
0x04
2
•
Temperature Value: 0xF060
~0x30D4 (-40°C ~125°C)
Produced by firmware.
Data
1 to 255
0x04
1
•
Humidity Value: 0x00~0x64
(0% ~ 100%)
Produced by firmware.
Data
1 to 255
0x84
0xCD: No Function
Produced by firmware.
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