Scan from String error

[Tuesday]

I am having a problem with 'Scan from String'.  I get an error message everytime I try to use it as follows: "NI-488: Command requires GPIB controller to be controller in charge".  How do I fix this?

[becktho]

Hi

It's quiet hard to help you, if you provide such little information (just imagine someone saying to you he's having problems with the telephone - you won't be able to help him if you don't know more). There can be lots of solutions if you just say you're having a problem with a function.

The best way is to attach the source and give a short but precise description of the problem. If you can't attach the code, even a picture (but please no *.bmp) of the source would help a little.

Thomas

[tst]

If you look before the 488 error, you should also see the line LabVIEW: An input parameter is invalid. Since I assume you're not using GPIB, this should be the one to interest you. Scan from String expects a string of a certain structure to enter it (that structure is determined by the string entering the Format String terminal, and can be configured by right clicking the VI and selecting Edit Scan String).

My guess is that you are feeding an empty string into the VI (use a probe to check), which is why you're getting the error. If this doesn't help, then you should do what becktho suggested. BTW, you should always read the help and use probes to check if things are working properly.

To learn more about LabVIEW, I suggest you try searching this site and google for LabVIEW tutorials. Here and here are a couple you can start with. You can also contact your local NI office and join one of their courses.
In addition, I suggest you read the LabVIEW style guide and the LabVIEW user manual (Help>>Search the LabVIEW Bookshelf).

[Tuesday]

Hi

You were right.  I tried to feed an empty string into Scan from String.  Thank you.  Sorry about the ambiguity in my question, I will attempt to be more detailed in the future.

Tuesday