tpc-usb600x

[fabio.intel]

Hi,

My problem is very easy (to explain). I want to acquire information from usb directly in my tpc.

I try to do it but I haven't the palette to create a phisycal channel....

thanks

[Christian Mergl]

Hi,

It depends on the tpc you are using!

If you have a tpc running a normal Windows XP, with LabVIEW installed then you only need to install the NI-DAQmx 8.5 driver and you will find the functions within the measurement I/O palette for working with your USB-600x.

BR, Christian

[fabio.intel]

Hi Christian,

thank you very much. I didn't find the function block to create the task (I supposed that it was on the pallete). Now I know that you can configure the task before to create the project. My new problem is another; how can I control the task timing in a VI? Suppose that I want to change the "timing mode" from "Finite" to "Continuous". Do you have to configure two different tasks?

[Christian Mergl]

Hi,

Why do you want to change the mode from "finite samples" to "continous"?

Christian

[fabio.intel]

Why not? Ok If you dislike it I have another. I want to change the scan rate...

[Christian Mergl]

Hey,

Changing a running Task from finite to continous is not possible. Changing the sample clock is possible, by using a counter as sample clock source, which is configured for pulse train generation. But this doesn't work for USB-600x!

Christian

[fabio.intel]

I configured the task timing in "continuous" way  but my usb 6008 doesn't work. I read the -200714 and the -1073807 code error.

I want to try again and so I can explain better my problem.

I know that other persons have the same problems with different code error. We can work only with the task timing in "on demand" way but we can go after signals under 40 Hz!!! I don't know what is my mistake.

[Christian Mergl]

Hi,

The explanation of the error says:

Error -200714 occurred at an unidentified location

Possible reason(s):

Acquisition has stopped because the driver could not transfer the data from the device to the computer memory fast enough. This was caused by computer system limitations.

Reduce your sample clock rate, the number of channels in the task, or the number of programs your computer is executing concurrently.

So maybe you aquire data on serveral channels with high sample rates, which couldn't be transfered via usb fast enough, or within your application you reading the data to slow, or other windows threads disrupting the application. There could be a lot of reasons! But keep in mind, changing the sample rate while running a continous application normaly takes no effect, because you are reading the data continously in a loop after the configuration of the task.

For the second error I can't find a description, but if you lost some numbers, maybe the following error is what you get:

http://forums.ni.com/ni/board/message?board.id=170&message.id=111863&requireLogin=False

Christian

Message Edited by Christian_M on 03-08-2007 09:20 AM

[fabio.intel]

Hi Christian,

   How are you? I hope fine. I have a lot of problems and I hope you can help me. I have to acquire a signal (continuos way) with my USB 6008 and I have to visualize it on my TPC. If I configure my timing task with 1000 Hz scan rate I read the -200714 code error. It's crazy!!! What is my error? You know that USB 6008 works until 10KS/s...

thanks a lot

[Christian Mergl]

Hi fabio,

Thank's, I'm fine, but I'm out of office this days, so it could take some time for a answer!

As I posted before, there could be a lot of reasons letting this error occur!

Which TPC do you have?

Which OS are you running?

Are using LabVIEW? Which version?

Which version of DAQmx are you using?

The best would be to first use a example for continuous acquisition, which could be found - assumed using LabVIEW - with the LabVIEW Example Finder (LabVIEW>Help>Find Examples) or under ...\National Instruments\LabVIEWx.x\examples\DAQmx\...

There you will find a example for testing this and also be able to have a look on the code!

BR, Chrisitan