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From: Armin Mueller on 21 Jan 2010 17:19
Dear NG,

I've got a legacy test stand that is running LabVIEW. Now I would like
to do some analysis and post processing using Matlab. What is the best
way to transfer live variable values from LabVIEW to Matlab?

* Via TCP or UDP? Seems to be cumbersome and error prone.
* An OPC server? When I see it right, Matlab doesn't like the NI OPC server.
* Any other idea?

Thank you for any hint!
Armin
From: ade77 on 23 Jan 2010 13:29
Armin Mueller <arm.in(a)web.de> wrote in message <hjajt8$61b$1(a)news2.rz.uni-karlsruhe.de>...
> Dear NG,
>
> I've got a legacy test stand that is running LabVIEW. Now I would like
> to do some analysis and post processing using Matlab. What is the best
> way to transfer live variable values from LabVIEW to Matlab?
>
> * Via TCP or UDP? Seems to be cumbersome and error prone.
> * An OPC server? When I see it right, Matlab doesn't like the NI OPC server.
> * Any other idea?
>
> Thank you for any hint!
> Armin

Why don't you use the MATLAB script node in LabVIEW.
You can do your post processing in MATLAB, and send the result back to LabVIEW in real time
From: Armin Mueller on 27 Jan 2010 15:25
ade77 wrote:

> Why don't you use the MATLAB script node in LabVIEW.
> You can do your post processing in MATLAB, and send the result back to
> LabVIEW in real time

Yes, you are right. This would work in many cases. I forgot to say that
Matlab is triggered by a top-level application called "BSA Flow" which
is used to operate a very special measurement device.

LabVIEW is running in parallel to get some common sensor data. Now I
would like to merge the measurement results with the sensor data. With
the Matlab script node, I would end in two Matlab sessions in parallel,
right?

Cheers,
Armin
From: ade77 on 27 Jan 2010 23:56
Armin Mueller <arm.in(a)web.de> wrote in message <hjq7fa$4f5$1(a)news2.rz.uni-karlsruhe.de>...
> ade77 wrote:
>
> > Why don't you use the MATLAB script node in LabVIEW.
> > You can do your post processing in MATLAB, and send the result back to
> > LabVIEW in real time
>
> Yes, you are right. This would work in many cases. I forgot to say that
> Matlab is triggered by a top-level application called "BSA Flow" which
> is used to operate a very special measurement device.
>
> LabVIEW is running in parallel to get some common sensor data. Now I
> would like to merge the measurement results with the sensor data. With
> the Matlab script node, I would end in two Matlab sessions in parallel,
> right?
>
> Cheers,
> Armin

Yes, you will end up with two MATLAB running independent of each other.
The original MATLAB used for the measurement device, will not have any effect on the MATLAB script node inside LabVIEW.
It is like you have 3 open excel file (3 instances of excel): they operate independednt of each other.
Note that the MATLAB script node is operating like an activex.

Just try it yourself, open MATLAB normally , type in a variable like a = 7; so 'a' is in your workspace,
then open LabVIEW put a MATLAB script node, and in the add input put a constant double(value = 9) ,
make the input variable 'a'
then inside the node, type c = a*6;
add output node 'c'
make an indicator, then you notice that your 'c' = 54.

So my point is this;
the normal MATLAB is running on its own, but when you simultaneously put the MATLAB script node in LaBVIEW, that is a different MATLAB entirely, and their workspaces are completely indepedent.

If you need additional help you can post in the LabVIEW forum
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