Question on DAQ Max-Error 200279

[zebro]

Hi There,

I have made a labview program that include a NI DAQ application for a NI 9230 card. The error message is :

Error-200279 occured at XXX.Vi

Possible reason(s):

The application is not able to keep up with the hardware acquisition.

Increasing the buffer size, reading the data more frequently, or specifying a fixed number of samples to read instead of reading all available samples might correct the problem.

Property: Relative To
Corresponding Value: Current Read Position
Property: Offset
Corresponding Value: 0

Task Name: _unnamedTask<1B>

What is the step to resolve this issue? I have attahed a screen shot of the program.

Thanks.

[Bob_Schor]

I won't look at screen shots of programs -- I can't read them clearly, I can't edit them, I can't tell what version of LabVIEW you are using, I can't examine multi-layer structures (such as Case Statements and Stacked Frame Sequences, which should never be used by someone who is not a Certified LabVIEW Developer, or better), etc.  Attach your code (the file ending in .vi).

Bob Schor

P.S. -- the title of your Post is wrong -- Error 200279 is not the same as Error -200279.

[mcduff]

The error means your buffer is filling up faster than you are emptying it. There are DAQmx VIs that allow you to increase the buffer size.

Looking at your screen shot I think your program needs refactoring.

mcduff

[zebro]

the current VI use two channel in the Daqmx read.vi, I just found if I use one channel, the program will run very well. how can I increase the buffer size?

[mcduff]

Look in the DAQmx palette. 

My guess is increasing the buffer will help to a point. The screen shot of your code screams refactoring.

mcduff

[Bob_Schor]

If you attach your VI, we can help you.  If you refuse to attach your VI, you are making it very difficult for us to help you.  It's your choice.  It should be a very simple thing to get DAQmx to sample all three channels at a reasonable speed.  When you do attach your VI, please tell us how many channels you want to sample, what sampling rate you want to use, and how many points you want to take at once (for example, "3 channels at 1 kHz, 100 points/sample").

Bob Schor

[keysuccess]

Attached is the VI, kind of complex. I need 3 channel, 12.8 kS/s/ch.

Thanks.

[RavensFan]

Your DAQmx code is missing some definitions as to what makes up a task.  So I have no idea how it runs at all.  The VI is broken.

You start a task, but never stop it.  So my guess is that the buffer overruns between calls of your VI.

Stacked Sequences = BAD.  They should be flat sequences and probably eliminated altogether.

Abuse of local variables, particularly when you have some controls there unwired.  Replace local variables with wires coming from the source.

Array to cluster then unbundle?  Why?  That is a pure Rube Goldberg.  Just use Index Array.