R&D Staff Tip of the Month

The R&D Staff Tip of the Month allows the software developers and quality assurance staff at National Instruments Electronics Workbench Group to showcase the features of NI Multisim that they know will be helpful to the design engineer.

R&D Staff Pick

One of my favorite features in NI Multisim 10 is the ability to natively read and write data to the LabVIEW measurement (LVM) file format. This allows you to integrate simulation data of board-level designs, with the acquired output of real hardware, via NI LabVIEW applications.

This interaction between Multisim and LabVIEW therefore opens many possibilities for advanced signal analysis, most notably to compare how a prototyped design compares to the theoretical simulated output. To make this task easier for the user, Multisim re-samples the simulation data by interpolating it from uneven simulated data, to evenly sampled measurements that can be written to the LVM format.

Try For Yourself

In this example we will learn how to easily export data to LabVIEW from NI Multisim using a shipping example.

1. Select File >> Open Samples.
2. In the samples folder, select Speechfilter.ms10
3. Click on the Open button
4. In the simulate toolbar, click on the green play button to begin simulation
5. Double-click on the oscilloscope measurement instrument identified by XSC2 (you will notice the waveform looks as it does in Figure 1)

Figure 1 - Waveform in the Multisim oscilloscope

6. In the simulate toolbar, click on the pause button to halt simulation
7. In the oscilloscope interface click on the Save button to save the simulation data to the LVM format.
8. In the Save Scope Data dialog box select the file type Text-Based Measurement File (*.lvm)
9. Click on the Save button

The Data resampling settings dialog box (as seen in Figure 2) allows you to interpolate the data in-between unevenly sampled time-value pairs generated by the SPICE simulator so that it can be properly mapped in an LVM file for further analysis.

In NI Multisim 10 you are able to select one of three interpolation methods (Linear, Coerce or Spline) as well as set the delta in-between samples in time or frequency domains.

Figure 2 - Data resampling settings dialog box

10. In this example we will use the default settings and click on the OK button.

The data is now ready to be exported to NI LabVIEW!

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