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[RT] Meaning of Timed Loop "reset at structure start"?

Using LabView RT the Timed Loop and also the Simulation Loop have a hardware clock feature called 1 MHz. Each iteration is done in sync with the hardware clock ticks.

 

But what's the difference between 1 MHz and 1 MHz <reset at structure start>? My guess:

 

  1. The first option starts the loop with the next hardware clock tick (waiting)
  2. The second option starts the loop immediately (so the loop is running with a "tick offset")
  3. The hardware clock "reset" does not affect other Timed or Simulation Loops running at the same time

 

Is this correct?

 

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Message 1 of 5
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Hi,

 

in the following link you can find further information about this topic.

 

http://zone.ni.com/reference/en-XX/help/371361H-01/lvdialog/loop_configuration_db/

 

I have a VI attached which shows you the difference between these two options in a practical example. Just try out the different options for the timed loop.

Without <reset at structure start> the timed loop wants to catch up a time delay after its first execution, with this option enabled it still works fine for the upcoming

iterations.

 

 

Kind Regards

 

Thomas

Message 2 of 5
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Thank you for your answer. Could you please make a screenshot or save it with an earlier version? I am using LabVIEW 2009 SP1, so I can not open your VI.

 

As for the link, the explanation about "reset at structure start" is quite brief.

 

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Message 3 of 5
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Hi,

 

I have attached screenshots now. You just need a Main VI and a Sub VI as you will see. 

If you do not use the <reset... function> the timed loop trys to catch up the 1kHz clock after the first run, so that the Sub VI does not work properly anymore.

 

Kind regards,

 

Thomas

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Message 4 of 5
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Did I understand it right according to the picture below?

 

1MHzR.png

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