DAQ No Signal in Test Window and 200284 Error

[ElecEng]

Hi!

I'm working on a university project to control the speed of a motor using LabVIEW.

My program seems to run successfully only the first time it in the day. If I try to run it again I get a 200284 error ("Some or all of the samples requested have not yet been acquired").  I've tried resetting the computer, and the devices in MAX. 

When I open the 4472 test panel in MAX, choose:

Coupling: DC

Rate: 20000

# Points to read: 2000 points

Aqusition mode: Continuous
Autoscale Chart: <check>

and press start, there is no waveform displayed on the chart. Occasionally when it does display a waveform it has a large amount of noise (spikes of up +-10V) when the reading should be 0V.

We have a PXI-1000B computer with a PXI-4472 DAQ card.  We are using LabVIEW 8.6 and MAX version 5.3.

I'll welcome any suggestions!

Thanks in advance!

[Burrito]

Hi ElecEng,

You said that it does run successfully the first time. Do you get a proper waveform in MAX before you try running the program? 

[ElecEng]

Hi Burrito,

Thanks for the fast reply!

I haven't tried that yet. I'll try today.

I'll also mention that a Korenix Jet I/O 6520 is being used for analogue output. This is connected over Ethernet and writes to this are in the same while loop as the DAQmx reads. I'm not sure if this could be related or not.  

[ElecEng]

I checked the signals in the MAX test panel today before running the program.

There was a large amount of noise on signals that should be 0V.  Some channels had + - 3V dips others had + - 10V.

[ElecEng]

The program ran successfully once without too much noise.

Now the program runs but with much more noise and it is very laggy.  The MAX test panel only shows a signal for finite aquisition.  It takes more than five seconds to display and there are spikes of + - 10V on all channels now.

[Burrito]

I can't say I'm familiar with Korenix products. I'm not sure how that could be affecting your results.

Would it be possible for you to post a screenshot to give a better idea of what you're seeing?