TDMS-ContAcq-IntClk Example on USB6009

[EI]

Hi.

I tried this example on USB6009 in labWindow 9.0. I get error in line 153, col 9 with return value of -200877. It something to do with buffer size. I request sample size of 400 on one channel, which should be ok as there is a buffer ( for up to 500 samples) in USB6009.

What is the cause??

thanks in advance.

Shane Buckley

[Liam_A]

Hi Shane,

I've had a look through some of our material here, and have come across some information that may be of use to you. It seems that this may be a bug with the shipped product regarding the sample intervals.

I have included the following link to a previous Forum article that I believe encounters a similar problem and the solution.

http://forums.ni.com/t5/LabWindows-CVI/Problem-in-ANSI-C-Example-TDMS-ContAcq-IntClk-Error-200877/m-...

With a USB 6009, as in your case, it may be that the 500 needs to be changed to 512, as per the linked problem.

I hope this helps and please let me know how you get on,

[EI]

Hi,

Thanks for quick reply. Yes, indeed 512 instead of 500 help to fix the problem but I tried an example TDMSreader to read the generated tdms file and it said TMDS Error with  "The property does not exist".

But TDMSreader work on file generated by an example TDMSwriter.

kind regards

Shane

[Liam_A]

Hi Shane,

Does the error give a location (i.e. line and character) for the "property does not exist"?

It may be the case that it is a property of the file to be read that hasn't been defined properley on either the writing or reading stage.

[EI]

Hi Liam,

It give no error location. It just said "property does not exist".

I will try to find error but I am very new to TDMS.

Regards

Shane

[Liam_A]

HI Shane,

It may be the case that the properties written by the TDMS Writer are the same as those looked for by the TDMS Reader, in which case, those supplied by the TDMS-ContAcq-IntClk Example may not be matching.

In this case it may be possible to match them in the example code, or perhaps you could try deleting the relevant section and saving the example as a separate file. The relevant section is the "DAQmx TDMS Configure Code" part.

Let me know how you get on!

[AndrewMc]

Hey Shane,

That TDMSReader example in CVI not being able to read arbitrary TDMS files is a known issue (CAR 198313).

There are certain parts of that example that read the values for these properties:

TDMS_FILE_DESCRIPTION

TDMS_CHANNELGROUP_DESCRIPTION

TDMS_CHANNEL_DESCRIPTION

You can modify the example to ignore those properties.

[EI]

Hi.

Many thanks for the reply. I will try this approach but at the moment I am being called to complete other assignment. I will get back to it when I fiinish which will probably be in early Jan.

I wish you and staff in NI a Merry Xmas and Happy new Year. Many thanks again for your support during the year 2010.

Kind Regards

Shane