NI-DAQ problem

[mr.collins]

Hi my name is Arturo Cortes.

im having a problem with the NI-DAQ using the USB 6008 DAQ. I start my VI and program the inlet port for data adquisition and conect it to a wave graph, at first time it runs with out a problem and reads perfectly the voltage sings but when i stop the VI and run it again it generates an error, after that the VI wont work again, some time if I close the LABVIEW and wait like 15 mins and reopen the VI it runs propertly but only the first time, if I stop it an run it the same error come out. i traied to change the samples to read and the rate but doesn't work. also I try in another computer and the sema thing happend. here is the error that always came out.

I hope some can help me to cerrect it and take continuos samples without any problem

[Lucianogob]

Hello, I'm sending to you a helpful link. http://digital.ni.com/public.nsf/allkb/611475F9BE62881E86256FDC0062B1BB?OpenDocument Thanks. Best Regards

[JÞB]

OK, what you have goining on here is a simple control issue- you are not controlling your task.  when you start a continious acquisition task it starts filling the device memory with samples untill you stop the task.  If you don't read them the memory gets full and you get that error.  1 way to avoid this problem is to use the DAQmx functions to specifically controll the task and pass the data out of the acquisition loop on a queue for processing or display.

This snippet shows an example of controlling a task properly

[John_P1]

Hi mr.collins,

Based on the task working the first time and failing on subsequent iterations, this sounds similar to an issue that NI has identified when using the 6008/6009 with certain external USB hubs when used with an EHCI host controller on Windows Vista or 7 (CAR 282875).  Does this describe your setup?  I'd be interested to know the following:

1. What chipset/motherboard are you using?  A link to the computer specs would be ideal.
2. What OS?
3. How are you connecting your 6008/6009?
4. What version of DAQmx?

Windows Vista introduced a EHCI driver re-write which we suspect (but have not confirmed) might be tied to this issue.  NI is looking into providing a workaround which would allow you to limit the number of outstanding requests via a DAQmx property node.

If you are not using a hub with Windows Vista/7 then please disregard my comment (although I'd still be curious to know the answers to the four questions posed above).

Best Regards,

[mr.collins]

hi Jhon

 thanks for your interest, im using a lenovo V360 computer but I also try it on a Dell, both of them are laptops.

both have Windows 7 x64bit, the conection of the usb 6008 is via USB port and the DAQmx 8.8.0

thanks for your time and support

[mr.collins]

sorry I forget to publish the specs of the lenovo computer.

http://www.drivershq.com/driver-update/graphics-video-adapter/intel/intel-r-q965-q963-express-chipse...

thanks

[mr.collins]

HI to all of you

today I try the Vi on a desktop that has windows XP, it works propertly but it pull out another issue. the VI is just a graph to show the voltage that the USB 6008 recives, i conect it to a variable power for testing but the graph keep moving on 0 volts only when the voltage input was over 1.8V it began to rise, i dont know why, i check the voltage input over the screws with a multimeter and always was a discrepansy bettwen the graph and the voltimeter. really I dont know why this is happening and also dont know how to correct it I hope you can help me.

THANKS and best regards

[Dennis_Knutson]

Sounds like you might have a wiring problem. You have not provided any information on how you have connected the signal to the DAQ device or how you have the device configured (i.e. RSE or differential).