Writing GPIB Commands in App Designer

Hello Matlab Community,

I am trying to migrate a labview VI functionality to matlab App Designer. We previously collected data through labview, then plotted it to matlab. We are using an HP4396B Spectrum/Network Analyzer. The hardware is really old and can't communicate with modern drivers. I would mirror the type of programming this example uses - https://www.mathworks.com/help/instrument/examples/reading-inphase-and-quadrature-iq-data-from-a-signal-analyzer-over-tcp-ip.html#d120e1234 - There is an oscilliscope example - https://www.mathworks.com/matlabcentral/fileexchange/69847-oscilloscope-app - that scans for local instruments and connects to a desired resource. It has the ability to change channels while inserting specific parameters.

I would love something similar so my team can input desired start/stop freqeuncy ranges, update the settings, run a single sweep, then plot the data to a UIAxes. I am able to connect to the instrument in a startupFcn, but when it comes to using fprintf, nothing happens. For example the command [fprintf(app.obj1, 'FORM4;CORR 0')] does not write to my analyzer when viewing the Test and Measurement Tool Communicate tab.

Note, having the fprintf commands work in a regular *.m script, but does not execute when placing them in my *.mlapp script. Last week was spent researching and I can't find any YT video or documentation over the syntax.

Sorry if this answer was already asked.

Thanks!

[Kristoffer Franzén]

Hello,

I'm wondering if you have found a solution for this, I have a similar problem.

Thanks!

[Blake Morrell]

Hi @Kristoffer Franzén,

What problem are you dealing with? I found that my analyzer was entering an error state along the way. I was remotely building this application without actually viewing my analyzer screen haha. What resloved my issue was sending a reset command.

To further build my application, I downloaded the oscilliscope app in my post, opened it and viewed the code. This helped tremendously for building mine from scratch.

[Kristoffer Franzén]

I'm trying to migrate TestPoint functionality to Matlab for doing hall measurements among other things. I need to communicate with several instruments over GPIB. I'm trying to get them to return an id in the startupFcn but to no avail.

I wasn't really sure where in the generated code it's best practice to connect to the instruments, so I thought I'd shoot a question your way, seeing that you also connected at the startupFnc.

Now I gather this is the way to go. I'll sure check the code for the oscilloscope and my instruments.

Thank you for taking your time to answer and for good tips!