Trying to take oscilloscope voltage data

[sahurley]

Hi,

I am trying to get the output voltage from my oscilloscope to track when my thruster is pulsing.  I've attached a picture of my vi and I am using a NI USB-6008 and a usb attached from the DAQ to the oscilloscope.  The timing isn't working correctly and when it writes to file the voltages are all the same and it's going hours past the amount of time I've run it.   Does anyone know why this is happening?

[RavensFan]

Your picture doesn't help us help you.  Most of the important stuff is buried in the DAQ assistant, and we can't click on a picture to open that and see how it is configured.

You talk about your oscilloscope, but you don't mention any details like its brand name and model number.  And your code doesn't show any attempt in trying to communicate with it.

As for running a long time after, your VI is only going to stop running when you press the stop button.  How long it takes to write all of that out to a file depends on those DAQ settings and how many waveforms you've put together in that Waveform VI.

The shift register you have serves no purpose because you never use the value coming in from the left side, and the intial data constant going into the left side of it isn't doing anything either.

[RTSLVU]

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@sahurley wrote:

Hi,

I am trying to get the output voltage from my oscilloscope to track when my thruster is pulsing.  I've attached a picture of my vi and I am using a NI USB-6008 and a usb attached from the DAQ to the oscilloscope.  The timing isn't working correctly and when it writes to file the voltages are all the same and it's going hours past the amount of time I've run it.   Does anyone know why this is happening?

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I don't understand why you have a DAQ attached to an oscilloscope.

If you want to get waveforms and voltage measurements from an oscilloscope you need to communicate directly to the oscilloscope.

[sahurley]

I am trying to communicate with the oscilloscope via the DAQ.

The DAQ Assistant I did: acquire signals -> analog ->voltage-> continuous.

The oscilloscope is a Tektronix TDS3014C.

I got the code from a class I took where we were reading voltages.  I did press stop (no need to be rude), but when I opened the spreadsheet it had gone on 3 days when I only ran it for 30 minutes.  The shift register is supposed to connect the timing mechanism and output all of the values taken to a spreadsheet, rather than solely the current cycle.  

[sahurley]

How do you connect the oscilloscope directly?

[RTSLVU]

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@sahurley wrote:

How do you connect the oscilloscope directly?

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Download the LabVIEW Instrument driver for your scope

http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=014E9F890ACE6DA0E0440003BA7CCD...

Usually examples for basic comunications are included.

[RavensFan]

A DAQ device acquires data.  An oscilloscope acquires data.  How do you expect a DAQ device to communicate with an oscilloscope?

You can probably find LabVIEW drives to communicate withe a Tektronics o-scope.  Look at their website.   Use Google.  Look here.  http://search.ni.com/nisearch/app/main/p/bot/no/ap/tech/lang/en/pg/1/sn/ssnav:idr/q/Tektronix%20-%20...

[sahurley]

I tried hooking it up directly, but the time is still wrong and the examples won't work - it only runs in NI express.

[RavensFan]

What do you mean by "hook up directly" and by "NI Express"?  There are lots of Express VI's in LabVIEW.

Try attaching your latest code.

[sahurley]

I don't mean an Express VI, I mean it is only running on NI SignalExpress.  I don't currently have a code because I was trying to use an example, but it doesn't work.  The only way I can get any data is in SignalExpress.  

The responses said not to use a DAQ board, but to directly hook up the oscilloscope so that's what I did (square usb in the oscilloscope to usb in the computer).