daqpad 6508 freezes during heavy usage

[sahrens]

I am having a problem running a daqpad 6508 in a heavy i/o envirnment. This problem seems to be platform dependant, and I'm wondering if there is some way I can slow the Daqpad's usb timing so it doesn't freeze.

The problem is this: when I run an i/o heavy application (proprietary software using the latest Nidaq drivers) using the 6508 on my 1.3 ghz Dell (win2k) I have no significant problems. However, when I run the same application with the same OS on an embedded platform, the application freezes consistently. The embedded platform is a 500 mhz K6 running on a ALI1541 chipset. Is it possible that the 500 mhz is just too slow to adequately handle USB timings of this nature? or is there some way I can adjust my device so it
runs slower?

Thanks,
--sa

[JustinBritten]

When you say "handle USB timings of this nature" and "heavy i/o" what are we referring to? How heavy is heavy I/O? Please give me some background on your program so I may determine just how CPU and/or bus intensive it may be.

The DAQPad-6508 is compatible with the USB 1.1 specification which states that maximum speeds are 1.5 Mbytes/sec. This is slower than PCI and other available busses.

The issue may also center around the USB driver for your embedded platform. Do you have any other USB devices that you could test out on this OS to verify that only the DAQPad is susceptible to the freezing problem you are seeing.

Furthermore, does the application generate an error or just lock up? What language are you programming in? Could you troubleshoot wh
ere the freeze occurs? During which calls to the NI-DAQ driver?

Regards,
Justin Britten

Applications Engineer
National Instruments