write / read tdm properties

[DavidS!]

Hi all,

I'm using LV7.1 and want to use the Write / Read TDM Properties example. Writing data works perfectly fine, but when I run the read example I get the error code 2558 Database could not be opened. I also have the 30 day trial of Diadem10 installed. Any ideas?

David

[Jochen]

David,

are you talking about the Write TDM File.vi and the Read TDM File.vi example? I haven't found the example that you are talking about. Could you please post the files to this thread?

Thanks,

Jochen Klier
National Instruments Germany

[DavidS!]

Jochen,
attached you can find the files. I downloaded them from the NI page.
Hope that helps.
David

[Jochen]

You simply need to double click on the Open Storage Express vi in the Read TDM Properties.vi and enter the correct path to the TDM file that you have created previously. Then everything should run find.

Jochen Klier
National Instruments Germany

[DavidS!]

Jochen,
thanks for your response. When logging in as admin it works fine.
but I ran into another problem, maybe you can give me a hand on that:
I would to store some test descriptive text to "Freier Text 1" of the Properties VI. The text is defined as a string and looks like

[Abtastfrequenz Hz] 10000
[#Scans/Messpkt] 81920
[Offsets V]    1.000000 2.000000 3.000000 4.000000
[Temperatur °C] 0.0
[Pbaro Pa] 0

I get back error 2574 (LabVIEW:  Der String, der an diese Funktion übergeben wurde, enthält Binärzeichen, die für .tdm-Dateien nicht gültig sind. Zum Speichern von Binärdaten sollten Datenkanäle für vorzeichenlose 8-Bit-Integer verwendet werden.) The function seems to recognise the numbers although the whole thing is defined as string. Why is that the case? Do you have an idea to go around it?
Regards, David

[Jochen]

I have done exactly the same thing but I don't get this error message (see attached tdm file). I have even added some non-displayable characters to the free text but it still worked fine. I tried with both, LabVIEW 7.1 and LabVIEW 8.0 but I can't reproduce this issue.
Does the error also occurr when the free text string is something simple like "Hello world"?

Jochen

[DavidS!]

Jochen,
no, with "Hello World" it works just fine!?!
David

[Jochen]

In this case please add the special characters that you are using (one after another) to test if there is one that results in the error. You could also try to copy and paste the string that you have posted to this thread to your string constant in LabVIEW because that's the way I used to add the string to the vi and this way I didn't see the error. If this solves the problem you could have a look at the hex display of your original string and the one that is working and compare them byte by byte. Maybe there is a special character that causes the error.

Sorry for the inconvenience but as I can't reproduce the issue I need your help to solve it.

Best regards,

Jochen Klier
National Instruments Germany

[DavidS!]

Hello Jochen,
I think I found the problem:
As soon as you insert an end of line in your string ,e.g. "Hello\sworld\r\n", error 2574 occurs.
So, it will not be a problem to work around it.
Thanks for your support.
David