Position encoder works with PCI-MIO-16E-4 but not with PCI-6062E, why?

[jonsar]

I am using A BNC-2090 to connect Agilent HEDS-6540 position encoder to my PCI-6052E. The application works fine with my 12 bit NI card PCI-MIO-16E-4, But with the new card I get extra counts in my position. ex 1052 pulses when it is only supposed to be 1000 counts in a complete revolution. This setup still works great with the old card, meaning I can just plug into the other card and run the same app on the same computer, just a different device number. I have not been able to figure this out.

[bman]

You might be seeing the affects of dithing with your signal. I'm not sure why it would be on one board, though not the other, one counter must be more sensitive. Anyway, dithering is caused by vibration or other outside forces that cause small glitches that add to the count total for the counter. There is a way around this, and that is to use a counte convertor. There is a page on this website that tells how to make one. The link is below. I would sugget trying this to see if it will fix the problem.

Brian

http://zone.ni.com/devzone/conceptd.nsf/2d17d611efb58b22862567a9006ffe76/6f25cba2cd73417786256869005e5fc3?OpenDocument