YASKAWA MP3000 Series, User Manual, Page: 422 / 435

2.16 Details on Protocols
MEMOBUS Protocol
2-404
MEMOBUS RTU Mode
 Reading the States of Coils
 Reading the States of Input Relays
When a message is received on a 218IFD Module using the MEMOBUS protocol, the CRC-16 is not
checked.
Note
7 • • • • • • • • • 0
(H)
(L)
(H)
(L)
CRC-16
(H)
(L)
Command
Slave address
Function Code: 01 hex
First address
Number of coils
The function code to read the states of coils is 01 hex.
Set the first address of the coils to read.
Set the number of coils to read.
Error checking
7 • • • • • • • • • 0
CRC-16
(H)
(L)
Response
Slave address
Function code: 01 hex
Number of data items
States of first 8 coils
States of next 8 coils
States of next 8 coils
The function code to read the states of coils is 01 hex.
This contains the length of the data item that was read in bytes.
This contains the contents of the data item that was read.
Error checking
7 • • • • • • • • • 0
(H)
(L)
(H)
(L)
CRC-16
(H)
(L)
Command
Slave address
Function code: 02 hex
First address
Number of relays
The function code to read the states of relays is 02 hex.
Set the first address of the relays to read.
Set the number of relays to read.
Error checking
7 • • • • • • • • • 0
CRC-16
(H)
(L)
Response
Slave address
Function code: 02 hex
Number of data items
States of first 8 relays
States of next 8 relays
States of next 8 relays
The function code to read the states of relays is 02 hex.
This contains the length of the data item that was read in bytes.
This contains the contents of the data item that was read.
Error checking