Yaskawa F7 Modbus - Manual (Page 24)

Message Formats 2-7
► Loop-Back Normal Response
The normal Loop-Back Test response is identical the command message.
Table 2.9 - Loop-Back Normal Response Message
Description Data
Slave Address 01h
Function Code 08h
Upper 00h
Test Code
Lower 00h
Upper A5h
Data
Lower 37h
Upper DAh
CRC-16
Lower 8Dh
► Loop-Back Fault Response
Table 2.10 - Loop-Back Fault Response Message
Description Data
Slave Address 01h
Function Code 88h
Error Code 01h
Upper 87h
CRC-16
Lower C0h
The fault response message contains the same slave address as the command message, indicating to the master which slave is responding. The
function code of a fault response message is the logical OR of 80h and the original function code of 08h. This indicates to the master that the
message is a fault response message, instead of a normal response message.
The error code indicates where the error occurred in the command message. Refer to the section Error Codes, Table 2-14, for more information
on returned error codes.