allign 2 double signals

[rk_t]

Hello All,

I had acquired 2 signals from the same motor but at different time during the day using Labjack U3 HV and stored them in a file as I want to compare them in future.

These signals are very similar in nature since they are of same motor. But I am not able to allign them since they were captured in "double" form.

Is there any way to allign them?

If not, can it be done if I use NI USB 6008 or similar hardware using "Analog -> Single channel -> multiple samples -> waveform" read in the DAQmx vi's,

store one of them as master and then compare the other one after acquiring?

Attaching the vi and files I used to store the signal.

I am using labview 2009 on windows 7.

Please help!

thanks!

[CsabaF]

Hi,

I guess you would like to see them on the same graph - try the build array vi with concatenate inputs enabled. This will build an array which can be shown on a single graph.

[GerdW]

Hi rk,

Is there any way to allign them?

Put your measurement data in waveforms. Manipulate the t0 of the waveforms to have the plots aligned…

General hint: when storing measurement data you should not only store the signal values, but also parameters like sample rate and start time!

[rk_t]

Thank you for your response CsabaF, but I dont want to see them on 1 graph, i want to allign the signals time wise to compare them and generate a pass/fail signal.

@GerdW,

How do I put my measurement data in waveforms? I can only get data in the form of double from the hardware.

The basic idea of my application is to compare the acquired data of the motor with a stored master. Check if they are within tolerance limits and generate a boolean according.

[GerdW]

Hi rk,

creating waveforms is rather basic LabVIEW stuff, you should have learned this after going through the beginner courses offered by NI…

See this:

Then Rnd() simulates your DAQ device.

Does the LabJack don't provide functions to read arrays of DBL data?

[rk_t]

Thanks GerdW,

I will try this in the next few days and let you know.

Thanks once again for your response.