Labview 7.1 and Matlab 7.4

[ManKind]

We had a vi working with Labview 7.1 : Unfortunately University upgraded the common version of Matlab to 7.4(R2007a) from 7.2 - and - the vi stopped working - no error messages while running the vi.

1. does Labview 7.1 support Matlab 7.4.0

2. Is there any patch DLL etc to resolve the problem?

Thanks for your help.

Mankind

[Ian Colman]

Hi,

I have a few questions to help better understand the issue that you are seeing:

How is Matlab and your LabVIEW VI being used together? Can I also ask what your VI does and what exactly happens when the VI "stopped working"? What do you expect to see and and what do you see?

Regards,

Ian
Applications Engineer
National Instruments UK & Ireland



Message Edited by Ian Colman on 03-03-2008 06:14 AM

[ManKind]

The Labview Vi analyses a matrix of numbers from our gas washout machine. It does, among other things, converts the matrix to a graph, shifts the axis based on the behaviour of our 3 parameters, integrates area under curve, calculates slope. Most of the graphic representation is done by Labview, while Matlab scripts are inserted to do the analytical bits.

The expected behaviour on loading the matrix(from a delimited text file) is for it to be represented as a graph. This is not happening. No error messages pop up!

Can you decipher this behaviour?

[Ian Colman]

Hi,

Right okay, I can't find any direct reference to an incompatibility anywhere but it is hard to search without knowing exactly how your VI integrates with matlab. Are you using a math-script node or just reading in an m file using file i/o vis? If you could send me a screenshot of this part of your LabVIEW code or better still attach your VI that contains the integration then I may be able to suggest a workaround for you. In the meantime I will continue to look into any fundamental incompatibilty issues.

Thanks,

Ian

[ManKind]

We use the Mat-script node. WRT screenshot, I would have to go through my supervisor, so it may take some time.

[Ian Colman]

Hi,

A screenshot would be usefull but it is not essential so don't worry if you cannot get hold of one.

If you importing mathscript from an m-file using the mathscript node then the directory may have changed since Matlab was upgraded. Can you right click on the node, select Import and confirm that you are importing from the correct file location.

Using the matscript node does not really interface with Matlab at all. It simply reads in mathscript in .m format. If the above doesn't work could you try turning on 'Highlight Execution' on (the light-bulb icon) and follow the code's execution before letting my know where abouts in your code it malfunctions.

Best Regards,

Ian

[ManKind]

Thanks,

I've got clearance to send the Vi. Can u give me ur email id.

[Ian Colman]

Hi,

Unfortunatly I do not have a direct email address that we can use. I will need your email address so that I can send you an email from our system that you can then reply to with your VI attached.

If you are not able to post your address then please give me a call on (+44) 01635 523 545 quoting Service Request 639916 and give your address over the phone.

Best Regards,

Ian

Message Edited by Ian Colman on 03-06-2008 09:38 AM

[ManKind]

No Probs: mn87@le.ac.uk

[Ian Colman]

Ok Thanks Mankind I have your code now. I will take a look at it and get back to you as soon as I can.

Regards,

Ian