Command
Field
Description
0001
Transaction ID
2 Bytes, identification of a Modbus Request/Response transaction
0000
Protocol ID
2 Bytes, 0000 = Modbus protocol
0006
Length Field
2 Bytes, number of following bytes
FF
Unit ID
1 Byte, 0xFF = Master device
01
Function Code
1 Byte, 01 = Read
0064
Starting Address
2 Bytes, address of the first register
0001
Quantity of Registers
2 Bytes, the number of required registers
Assuming the DO1 status is closed, the command returned by the device is as follows:
0x000100000004FF010101
Command
Field
Description
0001
Transaction ID
2 Bytes, identification of a Modbus Request/Response transaction
0000
Protocol ID
2 Bytes, 0000 = Modbus protocol
0004
Length Field
2 Bytes, number of following bytes
FF
Unit ID
1 Byte, 0xFF = Master device
01
Function Code
1 Byte, 01 = Read
01
Data Length
1 Byte, Data Length
01
Data
1 Byte, 01 indicates COM and NO is close
You can write 0 or 1 to the register, the value 0 indicates COM and NO are open, and the value 1 indicates COM
and NO are close.
Close DO1, the command is as follows:
0x000100000008FF0F006400010101
Command
Field
Description
0001
Transaction ID
2 Bytes, identification of a Modbus Request/Response transaction
0000
Protocol ID
2 Bytes, 0000 = Modbus protocol
C2000-A1-SDD1010-AB3 User Manual
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SinoCon Co., Ltd.
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