YASKAWA MP3000 Series - Page 400

2.16 Details on Protocols
Extended MEMOBUS Protocol
2-382
 Reading the States of Input Relays
 Reading the Contents of Hold Registers
7•••••••••0
(L)
(H)
(L)
(H)
(L)
(H)
Command
Length: 07 hex
MFC: 20 hex
SFC: 02 hex
CPU number
Reference address
Number of relays (n)
Set the length of the command.
Always 20 hex.
The sub function code to read the states of relays is 02 hex.
Specify 4 bits each for the destination CPU number and the source CPU number.
Set the first address of the relays to read.
Set the number of relays to read.
7•••••••••0
(L)
(H)
(L)
(H)
(L)
(H)
Response
Length: 03 hex +
((number of relays + 7)/8)
MFC: 20 hex
SFC: 02 hex
CPU number
(Relays 1 to 8)
Relays
(up to number of relays)
Set the length of the response.
Drop the portion after the decimal point.
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 states of the relays that were read.
7•••••••••0
(L)
(H)
(L)
(H)
(L)
(H)
Command
Length: 07 hex
MFC: 20 hex
SFC: 03 hex
CPU number
Reference address
Number of registers (n)
Set the length of the command.
Always 20 hex.
The sub function code to read the contents of hold registers is 03 hex.
Specify 4 bits each for the destination CPU number and the source CPU number.
Set the first address of the hold registers to read.
Set the number of hold registers to read.
7•••••••••0
(L)
(H)
(L)
(H)
(L)
(H)
Response
Length: 03 hex +
Number of registers x 2
MFC: 20 hex
SFC: 03 hex
CPU number
Data 1
Data n
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 states of the hold registers that were read.