2.16 Details on Protocols
Extended MEMOBUS Protocol
2-385
Ethernet Communications
Reading the Contents of Hold Registers (Extended)
Reading the Contents of Input Registers (Extended)
7 • • • • • • • • • 0
(L)
(H)
(L)
(H)
(L)
(H)
Command
Length: 08 hex
MFC: 20 hex
SFC: 09 hex
CPU number
Not used.
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 09 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)
(L)
(H)
Response
Length: 06 hex +
Number of registers x 2
MFC: 20 hex
SFC: 09 hex
CPU number
Not used.
Number of registers (n)
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 number of the registers that were read.
This contains the contents of the hold registers that were read.
7 • • • • • • • • • 0
(L)
(H)
(L)
(H)
(L)
(H)
Command
Length: 08 hex
MFC: 20 hex
SFC: 0A hex
CPU number
Not used.
Reference address
Number of registers (n)
Set the length of the command.
Always 20 hex.
The sub function code to read the contents of input registers is 0A hex.
Specify 4 bits each for the destination CPU number and the source CPU number.
Set the first address of the input registers to read.
Set the number of input registers to read.