Is anyone aware of a timing problem when using Notifiers ?

[SteveMoores]

In the attached doc is the vi that I am currently developing, the sequence has only been put in to aid my understanding of the problem. Simply, this vi waits on a notification and then sets/clears a variable that is exposed on an automation interface. The reference to the AI is passed in to the VI as part of the notification. The problem is that if I remove the sequence then the call to clear the flag does not work, the call is successfull ( no error in error out ) but the flag is not cleared. I ran the vi with execution highlighted and all works well. I removed execution highlighting and put a delay in the sequence of 1 second and all worked well, so I lowered the delay to 1ms ( as shown in diagram ) an
d all works well. Removing the delay results in the variable not being cleared. Does anyone have any bright ideas ? It would suggest that the data is not ready a the point I attempt to use it - but surely this breaks the labView paradigm !

[TonyRivera]

Try setting the 'ignore previous(F)' flag to true.

[Steven Bird]

I think setting this parameter may help the issue but the initial issue regarding the removal of the sequence structure and the variable not clearing could be due to data flow. By using the sequence structure you are forcing the execution flow. I think what was happening is that you were getting a kind of race condition that either a delay or a sequence structure help solve the issue.

Hope this helps, Steven Bird

[SteveMoores]

Thanks for the response, the system works as expected now.