User Manual

Chapter 8 Communication Functions
8 - 5
8.5 Modbus Protocol Reference
Transmission procedure
The transmission between the external control equipment and the inverter takes the procedure
below.
 Query - A frame sent from the external control equipment to the inverter
 Response - A frame returned from inverter to the external control equipment
The inverter returns the response only after the inverter receives a query from the external control
equipment and does not output the response positively. Each frame is formatted (with commands)
as follows:
Frame Format
Header (silent interval)
Slave address
Function code
Data
Error check
Trailer (silent interval)