One simple question

[Chata]

I want my Labview application to measure pressure 10 times (separatelly) and to remember each measurement value, which can be later statistically processed. What is the easiest way to do that.

Thx in advance 

[yenknip]

You will probably want to use an array. If you know that the data will always be 10 items, you can pre define an array of 10 elements and insert the data points into the array as they are measured. This is more efficient than building an array point by point as each data plot is measured.

[Norbert_B]

Chata,

that is a question which is not easily answered.

a) It has nothing to do with LabVIEW.

b) It is a very general question without any given specifics like "I want to analyze the signals offline without any acquistion going on the background".

c) "Easiest way" in software engineering is most often "not the best way in respect to performance or scalability or interfacing".  You should not start using "Quick'n'Dirty"-solutions.  Think first, then plan how to do it and then implement it. Don't start with the third step!

If you have planned your approach, then maybe somthing like a shiftregister will suite your needs.... or perharps file IO... or FGV/action engines...... nobody knows that right now!

hope this helps,

Norbert 

[altenbach]

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Chata wrote:

I want my Labview application to measure pressure 10 times (separatelly) and to remember each measurement value, which can be later statistically processed. What is the easiest way to do that.

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I really don't know what you mean by "seperately".

If you mean to do the same masurement repeatedly, you could place your measurement code inside a FOR loop and built an autoindexing array at the output tunnel. Most likely you can also setup a simple hardware timed acquisition of 10 points and do the 10 measurmenents in one simple operation.

The best way really depends on many factors. Do you have a few more details on your setup? Is the measurments rate e.g. 1/day or 1/millisecond?

[Chata]

Thank You all for help, eventhough I havent really understood the procedures.

I will try to explain it again: We have transducer that gives output in pC. Then signal goes to charge amplifier and then to DAQ card. Signal that we receive is polar (0 - 10V), and maximal pressure that we execpt is about 4000 bar. Now, we want to make 10 pressure test, one after another. We want our application to remember previous values of pressure and then, when we have summary of results (10 pressure values) to make further statistical analysis (mean, max, min, st. dev  etc.). I hope my problem is now understandable. I am not sure how to use arays in this aplication.

[GerdW]

Hi chata,

use a FOR loop to get 10 samples, wire the resulting array (auto-indexing!) to the standard math functions (mean, stdev in the math palette, array min/max in the array palette)!

All said before...

[Dennis_Knutson]

Of course, the other option is to simply setup the DAQmx Read (or DAQ Assistant) to return multiple readings. The data returned is an array directly or indirectly in a waveform or dynamic data.

[Cory_K]

I'm not sure why you chose 10 specifically.
If you have a reason for choosing 10 samples, make a for loop that reads the value from your DAQboard each iteration and stores it in an array.

If you are just noting that you want multiple samples, I would put the read in a while loop controlled by some boolean on the front panel.
I would need more specific information on what you would like your program to do so I can help you implement that plan.