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15. MODBUS RTU PROTOCOL
MODBUS RTU Communication Protocol
From:
To:
Version
V1.1
update:
2021/11/08
1.Transmission Format
Baud Rate
9600bps
Start bit
1
Byte width
8
Parity
N
Stop bits
1
Slave address
H10
2.Packet Format
Address
Function
Data
CRC
checksum
16bits
16bits
03: Function of reading multi registers
16: Function of presenting multi registers
N*16bits
16bits
3.Data types
Data
Types
Description
TEMP
Signed byte, 0.1
℃
resolution, formula: T*10, the temperature range is -30~97
℃
(when 25
℃
is displayed, the data transmitted by the protocol is 250
according to the above formula; When the display is -25
℃
, the data transmitted by the protocol is -250; when bit15 is 1, it represents a negative number, and
when bit15 is 0, it represents an integer;), when this value is 32767, it indicates that the corresponding sensor is faulty.
DIGI1
Unsigned byte, unit 1, data transmitted is 123 when 123 is displayed.
DIGI2
Unsigned byte, unit 10, data transmitted is 123 when 1230 is displayed.
DIGI3
Unsigned byte, unit 100, data transmitted is 123 when 12300 is displayed.
DIGI4
Unsigned byte, unit 100, data transmitted is 123 when 12300 is displayed.
DIGI5
Unsigned byte, unit 0.1, data transmitted is 123 when 12.3 is displayed.
DIGI6
Unsigned byte, unit 0.001, data transmitted is 123 when 0.123 is displayed.
DIGI9
Unsigned byte, unit 0.01, data transmitted is 12 when 0.12 is displayed.