02-13-2006 07:48 PM
I got error (200279) from DAQmx task while I continuously sample data. I think the error occurs due to high window process load which delays analysis process of my program. I understand that I lost data while I process my analysis. Please see the attached image that shows the error message.
I would like to know how to ignore the error. I am using Measurement Studio with C#. I tried ‘try and catch’ method, but it is not very effective. I think there should be DAQmx option that ignores lost data.
I know that I can try to increase buffer and reduce samples, but it is not very safe for everyday running application.
Thank you.
02-14-2006 11:33 PM
SM Instruments,
You should be able to set some DAQmx Read Properties to allow unread data to be overwritten. The first property is OverWrite Mode, which must be set to DAQmx_Val_OverwriteUnreadSamps. The acquisition will then continue to overwrite the unread samples with new ones. The next step is to use the RelativeTo and Offset properties to always read in the most recent group of samples acquired. The details of setting all of these properties can be found in the NI-DAQmx C Reference Help under NI-DAQmx C Properties > List of Read Properties.
Hope this helps!
Thanks,
Justin M
Applications Engineer
National Instruments
02-20-2006 08:05 AM
Justin,
Thank you for the suggestion, but could you please elaborate on the proper use of RelativeTo and Offset properties?
I am working on the same issue using PCI-6143 and LabVIEW 7.1. My program reads 16k samples per iteration at 250kS/sec.
I have set RelativeTo to "Most recent sample" and Offset to "-16,384".
On every iteration I get error -200277: "Invalid combination of position and offset. The position and offset specified a sample prior to the first sample acquired (sample 0). Make sure any negative read offset specified will select a valid sample when combined with the read position."
Thanks! Zador.
02-20-2006 11:03 AM
02-20-2006 03:30 PM
02-22-2006 02:04 PM
02-24-2006 01:03 AM
Hi Zador-
Thanks for sharing- that's a really useful algorithm to determine the read offset