Buffered Event Counting PCI-6602 vs. PXI-6602

[Peter M. Tappert]

I have an application for the PCI-6602 which uses buffered event counting.
I recently got a PXI chassis, some PXI-6602 boards and a MXI interface
between the computer and the chassis. Everything operates as I expected
with one notable exception. I am reading from the buffer as fast as it gets
filled. However, whenever the total number of counts received exceeds the
buffer size (using the PXI hardware only), I get a 10920 error. The data
appears as though two counter values are reversed. As I mentioned, this
problem does not occur when I use the PCI-6602 boards.

[Shea C]

Hello Peter,

Thank you for your question regarding using a PXI-6602. It sounds like you are getting a 10920 error when trying to read data from the counter. This error is fairly common. One reason that you may be getting this error is because the 6602 is not transferring data correctly to the PCs memory. It could be configured wrong. One possible solution may be to make sure that DMA transfers are used, and call the appropriate function to configure it. In LabVIEW add a call to Set DAQ Device Info.vi forcing the counter to have "up to 1 DMA channel" immediately before the CTR Control.vi where you start the counter. The following link lists some other possible causes of the problem.

http://digital.ni.com/public.nsf/websearch/8FB9091CB9BB452B8525642000554799?Open
Document

Other resources can be found on the ni.com website by clicking the support tab at the top of the home page. Then search from Technical Resources at the top of the page for your topic. I hope these resources help! Let me know if you need any other support with this issue.

Shea C.
Applications Engineering