Omron CJ1W-C113 - REV 02-2008 Operation Manual page 147

Transferring and Saving Data
Executed
Status
IORD/IOWR During
instruction IORD exe-
cution
During
IOWR exe-
cution
Data transfer During
bit read
During
write
During
save
CX-Position During
upload
During
download
During
save
Explanation
120
IORD/IOWR
instruction
IORD IOWR READ
DATA
--- --- ---
OK Busy OK
OK OK Error
OK Busy Error
Busy Busy Error
OK OK OK
OK Busy Error
Busy Busy Error
Note For when more than one CX-Position is used for one PCU.
The above table shows the operation that results when a data transfer func-
tion is executed (the "executed" row in the table) on the data for one axis from
the CPU Unit or CX-Position while a data transfer function is being executed
(the "status" column in the table) on the data for another axis from the CPU
Unit or CX-Position. (If data transfer functions are executed from the CPU Unit
at the same time, depending on the processing in the PCU, it may be neces-
sary to transpose rows and columns in the above table to identify the kind of
operation that will be performed.)
"---" in the table indicates a combination of functions that does not exist. (The
IORD instruction reads all data in one operation. The status "during IORD
instruction" does not exist.)
"OK" in the above table indicates that the functions will be executed. The sec-
ond function will be executed after execution of the first function has been
completed. However, if reading and writing (in whichever order) are performed
for the same data, depending on the timing of the PCU's internal processing,
the values that are read may either be the values before writing or after writ-
ing. (See the diagram below.)
Data transfer bit
WRITE SAVE
DATA DATA
--- --- ---
OK OK OK
Error Error OK
Error Error OK
Error Error OK
OK OK OK
Error Error OK
Error Error OK
Section 5-1
CX-Position
Upload Download
--- ---
Busy Busy
Busy Busy
Busy Busy
Busy Busy
OK OK
Busy Busy
(see note) (see note)
Busy Busy
(see note) (see note)
Save