How to avoid underFlowError error (code 10843)?

[bluesky2000]

I am trying programming PCI6534 now. I want to use double buffer pattern generator. I modified the example code (DOdoubleBufPatternGen653x.c)
to 20MHz. It can compile. but it generated 10843 error. How can I avoid this kind of error? Thanks.

[Filipe A.]

That error is due to the hardware limitation of your board. If you take a look at the 653x User Manual, page A-3, it states there that the maximum transfer rate when doing pattern generation is 20MHz. When the application starts going to close that value, you might start seing that error -10843.
Hope this helps.
Filipe Altoe
Application Engineer
National Instruments