Error: Creating SignalExpress Plug-Ins with LabView

[Measure1]

Thanks for all your help Juergen 🙂

Magically, I was able to create the LV step with no error. When I was building the new Source Distribution, I unchecked all 3 in the Additional Exclusions i.e.  "Exclude files from vi.lib, instr.lib and user.llb. This fixed the LabVIEW step in SE problem.

[Measure1]

Problem: 

- Theres no error in SignalExpress

- I can see my LabVIEW VI snippet  in SignalExpress

- When I run the LV step, the RTM instrument triggers and I get new data

- BUT I dont see the same waveform I observed in LabVIEW in the Data View of SignalExpress. See images below:

Image 1: No Error in SignalExpress 2012.

Image 2: Configure VI Tab showing my LabVIEW VI Snippet (Front Panel with data)

Image 3: Data View in SignalExpress.

When I run the LabVIEW step in SignalExpress, the waveform updates as shown in image 3. I tried different outputs in LabVIEW (array, chart,  graph), but they all give this jagged data. Am I missing a setting in SE?? Would anyone happen to know how to fix this?

[D-Cubed]

Hi Measure1,

The data look like they are coming from a noise signal.  Can you wire a physical scope to the device to see if you're getting the signal you are expecting?

Running a test panel within MAX would also indicate whether the issue is with the SignalExpress step, or with the device itself.  If you see a different signal in MAX, please post a screenshot of this.

Warm Regards,

[Measure1]

D-Cubed,

Im not testing a device. Im controlling a Rohde & Schwarz RTM Oscilloscope.

- When I connect a sinewave to the RTM, I can acquire this signal correctly in LV 2011 i.e. The VI used to acquire this sinewave, is the VI snippet from my first post.

- I can successfully load this VI in SignalExpress 2012 as a "run LabVIEW VI step" as shown in Image 2 above; with no errors.

Problem:

When I run  SignalExpress, I dont see the same waveform (sinewave) I acquired in LV. Rather I get the jagged signal shown in image 3 above. How come?

[D-Cubed]

Hi Measure1,

If you are putting the VI posted in your first post in this SignalExpress step, I have a feeling you will not likely get the signal you are looking for.  Since SignalExpress steps loop, it looks like you might be opening a VISA session, reading from your device, and closing your VISA session over and over again.  Ideally, you would open VISA once, do several reads, and then close the resource.

If this is working in LabVIEW, what is your motivation for moving it into the SignalExpres environment?

Warm Regards,

[Measure1]

D-Cubed,

Ultimately we want our end users to work with SignalExpress, not LV. 

How can I create a VI like the one you described; that would be interprated correctly in SignalExpress? I would like to view the waveform in SE.

Your help will be appreciated.

[DFGray]

To get an instrument to run properly in SignalExpress, using a user step, you will need to read the documentation on how to create a user step.  Included with SignalExpress is a user step template (<Program Files>\SignalExpress\UserStepTemplates) which contains the program structure needed to make this work.  The problem is that an instrument needs to be properly set up before it can be used.  Internally, SignalExpress supports various run phases (initialize, pre-run, run, post-run, finalize, etc.).  The documentation and template VI show how to use these.  You will need to properly initialize your instrument before you can take data from it.  However, you do not want to initialize it every time you take data from it.  You need to close the instrument when done.  All of this is handled by the template.

Run through the tutorial and example and, if they do not answer your questions, reply to this topic.  Good luck.