KonNad C2000-A2-SDD8020-DD3, User Manual

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0000 Protocol ID 2 Bytes, 0000 = Modbus protocol
0004 Length Field 2 Bytes, number of following bytes
FF Unit ID 1 Byte, FF = Master device
02 Function Code 1 Byte, 02 = Read
01 Data Length 1 Byte, Data Length
FF Data 1 Byte, Binary of 0xFF is "1111 1111", 1 is closed, 0 is open
5.2.2. Read DO Status (0x01)
Take the case of acquisition 2 channels DO as an example. The command is as follows:
0x 000100000006FF0100640002
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
0002 Quantity of Registers 2 Bytes, the number of required registers
Assuming the DO1 status is closed and the DO2 status is open. 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
C2000-A2-SDD8020-DD3 User Manual
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