Operation Timing - Omron CJ1W-EIP21 Operation Manuals

8 Message Communications
8-2-8

Operation Timing

Output Variable Operation and Timing
You can monitor the values of the output variables to determine the status throughout instruction execu-
tion. The following timing chart shows the operation of the output variables.
Execute
(1)
Busy
(Executing)
Done
Error
ErrorID
1
When Execute changes to TRUE, the instruction is executed and Busy changes to TRUE.
2
After the results of instruction execution are stored in the output variables, Done changes to
TRUE and Busy changes to FALSE.
3
When Execute changes to FALSE, Done returns to FALSE.
4
When Execute changes to TRUE again, Busy changes to TRUE.
5
Execute is ignored if it changes to TRUE during instruction executed (i.e., when Busy is TRUE).
6
If an error occurs, several retries are attempted internally. The error code in the ErrorID is not
updated during the retries.
7
When a communications error occurs, Error changes to TRUE and the ErrorID is stored. Also,
Busy and Done change to FALSE.
8
When Execute changes to FALSE, Error changes to FALSE.
8-26
(4) (5)
(3)
Changes to FALSE
because Execute
changes to FALSE.
(2)
0x0000
CJ-series EtherNet/IP Units Operation Manual for NJ-series CPU Unit (W495)
(8)
Changes to FALSE
because Execute
changes to FALSE.
(6)
(7)
0x1234