YASKAWA MP3000 Series - Page 402

2.16 Details on Protocols
Extended MEMOBUS Protocol
2-384
 Writing to a Single Hold Register
 Performing a Loopback Test
7•••••••••0
(L)
(H)
(L)
(H)
(L)
(H)
Command
Length: 07 hex
MFC: 20 hex
SFC: 06 hex
CPU number
Reference address
Register data
Set the length of the command.
Always 20 hex.
The sub function code to change the contents of a single hold register is 06 hex.
Specify 4 bits each for the destination CPU number and the source CPU number.
Set the address of the single hold register to change.
Set the contents of the single hold register to change.
7•••••••••0
(L)
(H)
(L)
(H)
(L)
(H)
Response
Length: 07 hex
MFC: 20 hex
SFC: 06 hex
CPU number
Reference address
Register data
Set the length of the response.
Always 20 hex.
The response will contain the sub function code that was set in the command.
Specify 4 bits each for the destination CPU number and the source CPU number.
This contains the address of the changed single hold register.
This contains the state of the changed single hold register.
7•••••••••0
(L)
(H)
Command
Length: 07 hex
MFC: 20 hex
SFC: 08 hex
CPU number
Test code: 0000 hex
Data AAAA hex
Set the length of the command.
Always 20 hex.
The sub function code to perform a loopback test is 08 hex.
Specify 4 bits each for the destination CPU number and the source CPU number.
Set the data for the test.
7•••••••••0
(L)
(H)
Response
Length: 07 hex
MFC: 20 hex
SFC: 08 hex
CPU number
Test code: 0000 hex
Data AAAA hex
Set the length of the response.
Always 20 hex.
The response will contain the sub function code that was set in the command.
Specify 4 bits each for the destination CPU number and the source CPU number.
If the test is successful, the response will contain the same data that was sent in the command.