How to force a new period to a timed loop?

[fpia]

Hello.

Here my question:

I need to change programmatically the period of a timed loop. This is not a problem but:

I have to wait up to the next loop to submit the new period value. For example if my previous period was 20 minutes, now I have to wait 20 minutes in order to submit a new period.

This beacause the code to change the period must be inside the timed loop itself. You can see what I mean in the attached image.

The subVI gets the new period from a operator console. It will be executed only at the end of the period previously configured.

My question is: Is it possible to force the timed loop to get the new value without to wait the execution of the previous period?

Thank you

fpia

[GerdW · Accepted solution]

Hi fpia,

sometimes it might be more useful to wait for 1200 seconds instead of 20 mins 😉

It has been suggested a lot of times before: instead of waiting for a long time with just a single call of a Wait function you should split that amount of time into several smaller pieces!

- Why don't you use a timing period of e.g. 5s and just count the iterations to know when 20 mins are over?

- Why don't you use the "Elapsed time" function to know when 20 mins are over?

[crossrulz]

Gerd beat me to it.  You really should make your loop iteration much smaller and then use a count of number of cycles before performing your next operation.  Then you can easily change how long to wait for each operation.

[fpia]

Thank you Gerd.

My labview experience is not very good. I believed that one iteration over 1200 seconds was less CPU consuming. This beacause I've several loops like that, not just one. So in my head I thougth to execute each loop in 1200 seconds and to "wake up" them (if necessary) with some function or someting that I don't know!

Anyway, because you wrote "it has been suggested a lot of times", I think your solution is better than what I tried to do. I'm going to write it.

Thank you for you suggestion.

fpia

[crossrulz]

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@fpia wrote:

My labview experience is not very good. I believed that one iteration over 1200 seconds was less CPU consuming.

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To the computer, anything more than a few milliseconds is an eternity.  So having 1 second loop vs 1200 second loop will do next to nothing to the CPU consumption.