Eaton DC1-124D1FN-A20N - Operating Mode Modbus RTU

7 Serial interface (Modbus RTU)
7.3 Operating mode Modbus RTU
144 DC1 Frequency Inverter 10/12 MN04020003Z-EN www.eaton.com
7.3 Operating mode Modbus RTU
Operating mode Modbus RTU (Remote Terminal Unit) transfers the data in
binary format (faster data rate) and determines the transfer format for the
data request and the data response. Each message byte that is sent contains
two hexadecimal characters (0 … 9, A … F).
The data transfer between a master (PLC) and the DC1 frequency inverter is
carried out according to the following sequence:
• Master request: the master sends a Modbus frame to the frequency
inverter.
• Slave response: the frequency inverter sends a Modbus frame as a
response to the master.
Figure 84: Data exchange between master and slave
￫
The frequency inverter (slave) only sends a response if it has
received a request from the master beforehand.
Start
SlaveMaster
Address (1 Byte)
Function code (1 Byte)
Data (N x 1 Byte)
CRC (2 Bytes)
End
Start
Address (1 Byte)
Function code (1 Byte)
Data (N x 1 Byte)
CRC (2 Bytes)
End