ABB A43 User Manual page 101

Communication with Modbus
Request frame A request frame has the following structure:
Slave Address
Example of
The following is an example of a request. (read total energy import, etc...)
a request
Slave address
Function code
Start address, high byte
Start address, low byte
No. of registers, high byte
No. of registers, low byte
Error check (CRC), high byte
Error check (CRC), low byte
Response frame A response frame has the following structure:
Slave Address
Example of
The following is an example of a response:
a response
Slave address
Function code
Byte count
Value of register 0x5000, high byte
Value of register 0x5000, low byte
...
Value of register 0x5017, high byte
Value of register 0x5017, low byte
Error check (CRC), high byte
Error check (CRC), low byte
In this example, the slave with the Modbus address 1 responds to a read
request. The number of data bytes is 0x30. The first register (0x5000) has the
value 0x0015 and the last (0x5017) has the value 0xFFFF
2CMC48001M0201
Revision: C
Function Code Address
Function Code Byte Count
101
No. of Registers Error Check
0x01
0x03
0x50
0x00
0x00
0x18
0x54
0xC0
Register Values Error Check
0x01
0x03
0x30
0x00
0x15
0xFF
0xFF
0xXX
0xXX
A43/A44
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