Synchronous acquisition 4 analog signal and independently count TTL impulse

Hello!
I'm have NI DAQ board PXI-6115. I have problem:
Need synchronous acquisition 4 analog signal and independently count TTL impulse. When value counter will, at example, 5000 acquisition must stop. I'm read program in LV 7.1 but have a problem. In HELP write:"You can create only one counter input channel at a time with this VI because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter". I make two different task, but error not disappear.
I don't know how escape this error?
Program VI with Front panel screen-shot in attach archive.
Message Edited by _Pavel_ on 05-23-2007 09:06 AM
Attachments:
Progr.zip ‏80 KB

Hey Pavel,
Thanks for contacting National Instruments support. Your program, in it's current state, is attempting to generate a finite pule train and count edges on the same card. Finite pulse generation is a two counter device, where one counter generates the pulse train and the other counter gates the generation, or goes high when the generation is to start and low when it is finishes. So no matter which counter you select for the count edges task you will get the error you describe.
Is it possible to use the pulses that you are counting as an external clock? If so then you could just generate 5000 pulses and you would only acquire 5000 samples.
I have attached a modified example from your code.
Let me know what you think. It only acquires 5000 samples as desired.
Regards,
Kenn North
Senior Product Manager - Search, Product Data
http://ni.com/search
Attachments:
Progr.vi ‏58 KB

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Attachments:
pwm.out.in.analog.out.in.vi ‏45 KB

Dear nathand thanks for your reply,
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Attachments:
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Hi there,
it seems that german is your mothertongue, so I'll reply on german.
Digitale Eingänge müssen Software getaktet werden, da nur analoge Eingänge Hardware-Takt Unterstützung haben!
Sie können den Hardware-Takt nur mit analogen Eingängen einsetzen, die, von einem Timer gesteuert, gepuffert Werte einlesen können. Digitale Größen verarbeitet der Hardware-Takt nicht.
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Attachments:
recording VI.png ‏332 KB
AI+CI+CO.png ‏72 KB

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PS - also see this FAQ Entry for more detail.

the_wine_snob wrote:
Products, like the Dazzle lineup, just do not seem to work, or work well. I would avoid such.
Although I now have a Canopus ADVC300 I previously used a Magix 'Movies on DVD' USB device. I found the results from this to be particularly good and, to my ageing eyes, I see very little quality difference.
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Insanity is hereditary, you get it from your children

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Greetings,
I am trying to create a small DAQ system that digitalizes a analog signal and displays the waveform and spectral analysis. I know that the analog waveform component receives and array to plot the waveform. However I am having doubts about how many samples I need to collect to create the exact graphs that is annexed to this post.
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Thanks
Attachments:
InverterWaveform.PNG ‏8 KB
SpectralInverter.PNG ‏8 KB

Recently I tried to made this program to aquire the analog data from a serial port based device. I am trying to use the waveform graph from the right in my program instead of the graph from the left.
I do know that I need to create an array to store the aquired elements and connect to the wave form graph.
Question is: What is the correct way to program that?
My serial device is programmed to receive an character and return a 0-255 number that corresponds to the aquired value.
Message Edited by Borges on 05-13-2009 02:31 PM
Attachments:
sample1.PNG ‏31 KB
sample2.PNG ‏28 KB

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- http://digital.ni.com/public.nsf/websearch/4D1435DF82EF494186256D8A006DD6D4?OpenDocument.
- http://digital.ni.com/public.nsf/websearch/4D1435DF82EF494186256D8A006DD6D4?OpenDocument.
To easily perform such a multi-channels analog acquisition, you can use the VI named "AI Acquire Waveforms.vi". You also can use an example provided with LabVIEW. You just have to browse the NI Example Finder in "Harware Input & output >> Traditional NI-DAQ >> General".
Best regards,
Benjamin
National Instruments France

Link digital and analog signal?

Hi, I am trying to "link" a couple of analog signals to a dital signal.
I have a torque transducer with a integral quadrature encoder. I am also monitoring a couple of other analog signals.
The 3 analog signals are being monitored through simultaneou sampling: 1Mhz for ~1sec
In these analog signals i am capturing certain events (peaks, etc).
What I would like to do is tie these events to the encoder which is tracking "angle" (rotational position).
For example, I determine that the peak torque occured at index 579,397 of the 1,000,000 element array. What was the angle of the encoder at index 579,397 ????
I am using 7.1
Thanks for the help!
Ryan
Ryan
LV 7.1

Ryan,
Because we share the same name, I've created an example for you.
Basically, we're using the analog input sample clock to latch the
position of the encoder (connected to the counter). In a finite
acquisition, the exact number of samples you request are generated on
the sample clock. Since we are starting the counter task first, we'll
be waiting on the analog input sample clock to start. This way, the two
tasks will be exactly synchronized. Please let me know if you have any
additional questions.
Good luck!
Ryan Verret
Product Marketing Engineer
Signal Generators
National Instruments
Attachments:
AI_Encoder_Sync.vi ‏99 KB

Synchronous acquisition 4 analog signal and independently count TTL impulse

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