Zero Function on waveform data

[Rhys_CKTC]

Would you say do something like this RavensFan?

Attached VI. Loop without diagram disable.

Ideally it is a single value i would like to use to tare the data.

Rhys

[RavensFan]

That's basically it.

You still had the unnecessary extra waveform split and unbundle.  I cleaned up the code and made it simpler.

[irfaanz]

hallo Ravensfan,

i am beginner in LabVIEW, and i want to acquire data using loadcell. this case actually same with mine and i want to use this vi for my task, but i want to set the averaged value from sum of several channel. because i want to acquire multiple data (8 channel input).

device that i use: cDAQ 9188 cahassis and C series module 9201 (dsub)

in my case i have 8 channel input data that i want to acquire. and there are summing operation of some channel to get the value F (force) for each axis. here the summing operation:

ch 1 + ch 2 = F_x

ch 3 + ch 4 = Fy

ch 5 + ch 6 + ch 7 + ch 8 = Fz

thing that i want to ask, how i split the data from the DAQmx read function (highlighted in pic) to be 8 output? then i want to use numeric (add) function to do a summing operation and perform null offset each value after summing (F_x Fy Fz ).

i hope you reply this message and i'll appreciate it. i don't know should i make a thread or just reply your message because i really need your help. thank you.

[GerdW]

Hi irfaanz,

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@irfaanz wrote:

in my case i have 8 channel input data that i want to acquire. and there are summing operation of some channel to get the value F (force) for each axis. here the summing operation:

ch 1 + ch 2 = F_x

ch 3 + ch 4 = Fy

ch 5 + ch 6 + ch 7 + ch 8 = Fz

thing that i want to ask, how i split the data from the DAQmx read function (highlighted in pic) to be 8 output?

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In your image you are reading only one channel instead of proposed 8 channels…

Once you read multiple channels you just use IndexArray to get the waveform of each channel, then you just use Add functions as needed…

[irfaanz]

thanks for reply GerdW,

i choose this analog 2D DBL signal on daqmx read function instead 1D waveform, is it true?

is it true signal should i choose?

and i've make a sum from each channel to get Force value. is it correct with my new program? i just want to makesure. thankyou

[0Forest0]

I think you got dt error on first itteration.

[irfaanz]

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@0Forest0 wrote:

I think you got dt error on first itteration.

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I'm sorry, i don't reall understand why i got an error. Would you like explain to me about it? And why your vi is different with mine? Do you simpler my vi? Thankyou, i hope you reply my message.

[0Forest0]

Hi, I think you got the error because on the first iteration shift register had initialised by default value. And this default value has dt=1. But you got a new value with dt not equal 1. And minus vi showed error.

In my case the feedback node has got initialised on first iterration with your first value with dt not equal 1. And then minus vi has two same values on first iterration.

[pahlevi28]

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@0Forest0 wrote:

Hi, I think you got the error because on the first iteration shift register had initialised by default value. And this default value has dt=1. But you got a new value with dt not equal 1. And minus vi showed error.

In my case the feedback node has got initialised on first iterration with your first value with dt not equal 1. And then minus vi has two same values on first iterration.

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yeah i see.. Before you told me i'm still use that program, after a few seconds it's running, i push the 'tare' button for a few seconds, to store updated mean data to 'minus-ing' value, and it updated the offset data and it's not error as the first iteration. Thanks for correction