Synchronization I/O signals

[nicop92]

Hi everybody.

I have written a LV code for switching on and off a group of six lasers and record their intensity output every n seconds for 24 hrs.

It works quite well but after a certain number of iterations the recording/switching operation gets out of sync.

Might anybody help me out with that?

[GerdW · Accepted solution]

Hi nicop,

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@nicop92 wrote:

It works quite well but after a certain number of iterations the recording/switching operation gets out of sync.

Might anybody help me out with that?

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This is because you use a hardware-timed DAQmx task and an additional Wait in your loop. Delete this Wait function!

Btw. you do some serious Rube-Goldberg code in your VI! You REALLY should cleanup that monster!

Example:

Those offset values should be provided as an array instead of 4 scalar values…

[nicop92]

Hi Gerd.

Thank you very much for your reply!

Are you referring to the wait function I have highlighted in the attachment?

Cheers

PS: yes, it's quite intricate. I'm trying to simplify it as much as possible

[GerdW]

Yes!

When you set a timing in your DAQmx task then you just request a fixed amount of samples at DAQmxRead, which also sets the iteration time of your loop! (Simple math of samplerate*number of samples…)

Btw. don't forget to delete that additional wait function in the case structure, where you write the data to a file, too!

[nicop92]

Thank you very much Gerd.

Just one more question:

If I remove the the wait function you pointed out in the

beginning the data acquisition gets too fast (I cannot see a thing on waveform charts).

Could you please advise?

[nicop92]

Sorry Gerd!

Your last message notification got visualised in delay.

You're right: just set the samples number in the write functionality.

Cheers