Mitsubishi Electric MELSEC iQ-R Series User Manual page 531

Non-conversion variable
■Processing procedure
C24 processes non-conversion variable according to the following procedure.
C24
Data transmission
"ABCD"
Data reception
"ABCD"
(Byte swap)
"ABCD"
Disable byte swap
Swapping
send data
"ABCD"←"BADC"
(Byte swap)
"ABCD"
Disable byte swap
Swapping
receive data
Enable byte swap
"ABCD"→"BADC"
Appendix 5 Operation Image and Data Structure of Predefined Protocol
(Fixed length/Variable length)
(Data length/Maximum data length)
(Unit of stored data)
When "Byte swap" is 'Disable'
Unit of
Lower byte + Upper byte
stored data
'B'
'A'
D0
(42h)
(41h)
'D' 'C'
Data D1
(44h) (43h)
storage
area
CPU device
G device
Send data
Enable byte swap
When "Byte swap" is 'Enable'
Unit of
Lower byte + Upper byte
stored data
'A' 'B'
D0
(41h) (42h)
'C'
'D'
D1
Data
(43h)
(44h)
storage
area
(Fixed length/Variable length)
(Data length/Maximum data length)
(Unit of stored data)
When "Byte swap" is 'Disable'
Unit of
Lower byte + Upper byte
stored data
'B' 'A'
D0
(42h)
(41h)
'D' 'C'
D1
Data
(43h)
(44h)
storage
area
CPU device
G device
Receive data
When "Byte swap" is 'Enable'
Unit of
Lower byte + Upper byte
stored data
'A' 'B'
D0
(41h) (42h)
'C' 'D'
Data D1
(43h) (44h)
storage
area
Lower bytes only
'A'
D0 00h
(41h)
'B'
D1
00h
(42h)
'C'
D2
00h
(43h)
'D'
D3
00h
(44h)
C24
ignores data of upper bytes
Lower bytes only
'B'
D0
00h
(42h)
'A'
D1
00h
(41h)
'D'
D2
00h
(44h)
'C'
D3 00h
(43h)
C24
ignores data of upper bytes
Lower bytes only
'A'
D0
00h
(41h)
'B'
D1
00h
(42h)
'C'
D2
00h
(43h)
'D'
D3
00h
(44h)
C24
stores 00h to upper bytes
Lower bytes only
'B'
D0
00h
(42h)
'A'
D1
00h
(41h)
'D'
D2 00h
(44h)
'C'
D3
00h
(43h)
C24
stores 00h to upper bytes
APPENDICES APPENDIX
A
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