YASKAWA MP920 User Manual page 270

Appendix B 218IF Messages
B.2.2 MEMOBUS RTU Mode
Single Holding Register Change
Command
7 0
Slave address
Function code: 06H
(H)
Holding register No.
(L)
(H)
Write data
(L)
(H)
CRC-16
(L)
Response
7 0
Slave address
Function code: 06H
(H)
Holding register No.
(L)
(H)
Write data
(L)
(H)
CRC-16
(L)
Loopback Test
Command
7 0
Slave address
Function code: 08H
(H)
Test code
(L)
(H)
Data
(L)
(H)
CRC-16
(L)
Response
7 0
Slave address
Function code: 08H
(H)
Test code
(L)
(H)
Data
(L)
(H)
CRC-16
(L)
The function code is 06H when a single holding register
is written.
Set the address of the holding register to be changed.
Set the data contents to be changed.
Error check
The function code is 06H when a single holding register
is written.
The address of the changed holding register is returned.
The changed data contents are returned.
Error check
The function code is 08H with the loopback test.
Set the test code.
Set the test data.
Error check
The function code is 08H with the loopback test.
If the test is completed normally, the same value is returned
as for the command.
If the test is completed normally, the same data is returned
as for the command.
Error check
B-22