choice of graph

[ameletudiante99]

Good morning ,

I acquire 6 parameters at 100 kHz; for a duration between 3 min to 50 min I would like to add a list for parameters for the user to choose which signal among the signals of 6 traced parameters; I use while loops for continue and finite mode; I am looking for a functionality that allows me to display the signals after I have stopped the acquisition?

I use an index array, it's not very pretty; once the acquisition is complete I no longer have anything displayed; I tried to get it out of the loop, it doesn't work.

thank you in advance

[GerdW]

Hi Amelie,

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@ameletudiante99 wrote:

I am looking for a functionality that allows me to display the signals after I have stopped the acquisition?

I use an index array, it's not very pretty; once the acquisition is complete I no longer have anything displayed; I tried to get it out of the loop, it doesn't work.

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When you want to use data after the loop has finished then you need to wire the data out of the loop: THINK DATAFLOW!

It seems you don't save the measurement data anywhere!?

You have been told to learn some basics: did you (yet)?

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@ameletudiante99 wrote:

I acquire 6 parameters at 100 kHz; for a duration between 3 min to 50 min

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So you collect 6*100kS/s*3min*60s/min*8Byte/S=864MB of data (minimum, upto 14.4GB for 50min): you should write the data to a file. DAQmx can do this automatically for you…

Recommendation: you should NOT handle this amount of data just in memory!

Strong recommendation: don't display all those data in a graph at once…

[PinguX]

Hi,

50 min * 100 kHz * 6 parameters = 14 Go of data.

I suggest you save the acquired data in TDMS files, so that you can read them once the acquisition has stopped.

Otherwise you will run out of memory.

[ameletudiante99]

yes, I record on TDMS files I use the daqmxConfigure logging VI;

yes I don't want to display everything on a graph but only part of it to see the shape of the signals

[GerdW]

Hi Amelie,

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@ameletudiante99 wrote:

I don't want to display everything on a graph but only part of it to see the shape of the signals

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So you should decimate your data to a reasonable amount.

Example: instead of 100kS/s you may reduce this to 3S/s (min, mean, max), so decimate by a factor of 33k. After 50 mins you will have 9000 points in your graph (per plot)…

[ameletudiante99]

yes, yes I understand but I want a solution to display the signals outside the loop; I can't program it

[GerdW]

Hi Amelie,

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@ameletudiante99 wrote:

I want a solution to display the signals outside the loop;

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Outside of the loop

• while the loop is still running?
• after the loop has finished?

After the loop you can implement my previous suggestion (decimate, output tunnel).

While the loop still runs: decimate, then use a chart inside the loop…

What do you have problems with? (Mind to take the Training resources?)