What happens to the execution state after the sequence program resumes?
- Last UpdatedJul 19, 2024
- 1 minute read
When the sequence program resumes and the event is caused by:
-
failover or by AppEngine shutting down and starting up, the execution state goes from Initializing to the execution state it was in before the event occurred.
-
switching the Sequencer object offscan and then onscan, the execution state goes directly to the execution state it was in before the event occurred.
The following table shows how attributes and features behave after the sequence program is resumed:
|
Attribute or feature |
Behavior |
|---|---|
|
On Entry Outputs |
are not written again when AutoResume is true |
|
Timers |
are frozen (excluding the time during failover, object offscan or object shutdown) and continues if AutoResume is set and the execution state before the failover event was Running or RunningSingleStep |
|
Step Execution |
is in the step body of the last active step Note: After switching offscan and then onscan, the active step is the next step if the restart/failover happened after the step condition was met (in case of a large scan period) . |
|
Current.StepTimerRunning |
persists the state of the timer so conditions can be evaluated accurately |
|
Current.JumpTimerRunning |
persists the state of the timer so conditions can be evaluated accurately |
Note: After a failover event, the object goes to the last (current) step and is put in RunningHeld state. If it happens that the failover event occurs after the condition is met and after the OnExit outputs are written then OnExit outputs are written again when the Resume or Advanced command is issued.