Single holding register change loopback test – Yaskawa MP920 Communications Module User Manual
Page 271

Appendix B 218IF Messages
B.2.2 MEMOBUS RTU Mode
B-22
Single Holding Register Change
Loopback Test
Slave address
Function code: 06H
Write data
(L)
(H)
CRC-16
(L)
(H)
Holding register No.
(L)
(H)
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
Command
7
0
Slave address
Function code: 06H
Write data
(L)
(H)
CRC-16
(L)
(H)
Holding register No.
(L)
(H)
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
Response
7
0
Slave address
Function code: 08H
Data
(L)
(H)
CRC-16
(L)
(H)
Test code
(L)
(H)
The function code is 08H with the loopback test.
Set the test code.
Set the test data.
Error check
Command
7
0
Slave address
Function code: 08H
Data
(L)
(H)
CRC-16
(L)
(H)
Test code
(L)
(H)
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
Response
7
0