PCI 6115 - Simultaneous Sampling Error -201309

[brehidran]

We currently have a VI that simultaneously logs data from 4x PCI 6115's. The VI is setup to use the "DAQmx Configure Logging (TDMS)" VI for streaming data to disk. Everything has typically worked out with the ability to record data from up to 16 channels at 1 MS/s simultaneously.

Unfortunately as of late when some users have been using the VI, an error occurs and that error is given as :

The "DAQmx is Task Done" is in a loop after the "DAQmx Start Task" vi is executed. The purpose is to wait for the finite number of samples to be acquired, give a notice of progress, then finish the task. The oddity is that this error is not consistently reproducible, and is neither rare nor common. (The users recall it occuring about 1 in 6 times per use). It is kind of scary because the users are not able to predict when the error will occur or see a pattern in its occurence. Typical end-users do not have any idea how to use labview so they have been letting this error occur for a while. If I can provide more information to narrow down the root of the cause, I will gladly assist.

[Skirpt]

Hi Brehidran,

Looking at the information available about the error that you are receiving I found the following KB http://digital.ni.com/public.nsf/allkb/C2732E5402ED80CC86257951004F7615. The KB suggests that one possible cause of this issue is that the file size is too large. This seems possible considering how many samples you are taking. Could you see if the runs that don’t fail are close to the allotted 4 GB file size?

[brehidran]

Skript,

Thanks for you response. When the error appears for the users, they are sampling about 6 channels at 100 kS/s, not very fast at all. The file sizes are much less than 4gB; probably around 100 mB or so.

-Brehidran

[John_P1]

Is it possible your app is trying to append to a file that was created by a different user account?  Perhaps the current user of the software does not have write permissions for the file in question.

Best Regards,

[brehidran]

Hi John,

Thanks for the response. I cannot say for certain if it's a permissions problem; it sure sounds like it. The computer is running windows 7 with a local administrator account. The  filename to which the tdms logging occurs is generated by time stamp in a state prior to the wait for a start trigger. The program should never be logging to an existing file. I will double check to make sure the program is not attempting to do this, but like I said it works MOST of the time.

Regards,

Brehidran