YASKAWA GPD 315/V7 - Chapter 4; Modbus RTU Message Format; Message Functions; Table 4-1 Supported Modbus RTU Function Codes

GPD315 Modbus RTU Technical Manual TM 4325
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Chapter 4
Modbus RTU Message For
mat
Message Functions
In communicating to the GPD315 drive via Modbus RTU, there are three message functions
available. The master specifies the function to be executed by the slave according to the function
code. The following table shows the types of function codes available, and the length (quantity)
and contents of the message according to the function.
Table 4-1 Supported Modbus RTU Function Codes
Command Message
Response Message
(Normal)
Function
Code (hex)
Function
min. (bytes) max. (bytes) min. (bytes) max. (bytes)
3 Read Multiple Registers 8 8 7 21
8 Loop-back test 8 8 8 8
10 Write Multiple Registers 11 25 8 8
The message format varies depending upon the function of the message. For each function,
there is a command message from the master and a response message initiated from the slave.
The following sections review the format of the command message and the response message
for each function.