time

[dromar2222]

Hello to all
I want to display and record the temperature for a time step of 15 minutes.  I used in CDAQ; continuous samples, Rate 1, samples to read 1

I avoided modifying the parameters so as not to have synchronization problems. I want to use if condition to record the temperature with a chosen time step..

How I can do it? Any Helps Please

[GerdW]

Hi dromar,

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@dromar2222 wrote:

I want to display and record the temperature for a time step of 15 minutes.

…

I want to use if condition to record the temperature with a chosen time step.

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Please provide your definition of a "time step"…

Please also provide your definition of "using an if condition"…

Do you want to measure your signals for 15mins? Then you just need to run your loop for 15*60=900 times, when you read 1 sample each 1 second!

[dromar2222]

Thank you for your feedback

what i want is to record values every 15 min.. when I do 15*60 = 900.. it starts recording in every 15 min but at some point it stops and it displays an error

you find attached the error and the schema

[GerdW]

Hi dromar,

simple solution: don't use ExpressVIs! (No DAQAssistent, no WriteMeasurementFile, no SplitSignal, no FromDDT, no MergeSignal…)

Use plain DAQmx functions, use simple WriteTextFile, set reasonable chart history size…

[JÞB]

It looks like you may have configured your acquisition as a "continuous".  That causes the device to start storing samples in the output buffer.  If you don't read them all eventually, the buffer will fill up and you will get the error you see.  Not many devices can actually hold 900 seconds of data! And I doubt you are really interested in all of the data between second 1 and second 901.  

You would want to use a "Finite" acquisition to take a specific number of samples starting at each 15 minute period.