PXI-6602 angular position measurement and interrupt transfer mechanism

[chassan]

Hello,

I am trying to measure the angular of 8 quadrature (incremental) encoders using each of the 8 channels of a PXI-6602 (1 encoder per channel).  I realize the PXI-6602 doesn't have enough DMA channels to handle all of the measurements, so I had planned to use interrupts for all 8 channels.  However, when I try to set the data transfer mechanism in DAQmx, it says the property is not supported by the device.

Does this make sense?

Has anyone successfully done this or someting similar?

Thanks,

Chris 

[JordanG]

Hey Chris,

The PXI-6602 device contains three DMA channels and eight counter/timers. From my understanding, you can simultaneously perform three high-speed and five lowerspeed, interrupt-based, buffered operations (not all 8 interrupt-based). This could be the source of the error you are receiving. What exactly is the error and is there a number associated with it? Try implementing this setup. I've also attached an article with detailed instructions on using the data transfer mechanism.

http://digital.ni.com/public.nsf/allkb/C326F7D33CA6DB0E86256DFE008043B7?OpenDocument

Jordan G