Chapter 5. Integrated Design and Academic Features
5.1. Integrated Design with Multisim and Other National
Instruments Products*
Integrated Design with Other National Instruments Products
LabVIEW
National Instruments LabVIEW is a graphical programming environment that can be used to automate test and measurement functions, for the purpose of testing and validating designs. Multisim data saved in .LVM or .TDM format can be easily loaded into LabVIEW using express Virtual Instrument (VI) technology. Simulation data can then be overlaid on top of measured results to quickly and easily verify designs.
Loading .LVM and .TDM Data Files
To load Multisim simulated data that were saved in a .LVM or .TDM file, use the Read from Measurement File Express VI. This VI is located in the Programming/File IOpalette. For help on this file, consult the LabVIEW help file. The Express VI can be configured to read either .LVM or .TDM files.
Figure 5.1.
Read from Measurement File Express VI
Note: The following only applies to .LVM files.The EOF? output terminal of the Express VI indicates true if there is more data contained in the .LVM file. This value is especially useful when reading data that were saved from a Bode Analysis, or from any plot window with more than one graph display. Simply place the Read From Measurement File Express VI into a while loop, with the EOF? output terminal wired to the exit condition terminal.
Note: The following only applies to .TDM files. To load .TDM files into LabVIEW which contain multiple graphs, lower level storage express VIs are required. Figure 2 below gives a demonstration of how one might load multiple graphs from a .TDM file.
Figure 5.2.
Loading Multiple Graphs from a .TDM File
LabVIEW Based Virtual Instruments in Multisim
For further information on LabVIEW based Virtual Instruments in Multisim, consult the LabVIEW Virtual Instruments text in Section II.
SignalExpress
SignalExpress introduces an innovative approach to configuring your measurements using intuitive drag-and-drop steps that do not require code development. Unlike traditional benchtop measurement tools, SignalExpress combines the optimal balance of measurement functionality and ease-of-use to assist designers in streamlining a variety of applications: Design modeling.
Loading Multisim Data into SignalExpress
To load simulated data into SignalExpress, simply use the Load from LVM step, select Add Step/Analog/Load and save Signals/Load from LVM. Choose the file name to load, and select the traces to import. Use the Domain field to choose from either Time, or Frequency data. Click close and run the SignalExpress workbench file to load the Multisim data.
Figure 5.3.
SignalExpress Load from LVM Step
ELVIS
National Instruments ELVIS is an ideal companion to any electronics lab that uses Multisim.
ELVIS provides a breadboard prototyping environment, with built-in instruments including a Function Generator, Digital Multimeter (DMM), Oscilloscope, and Variable Power Supplies. The breadboard is detachable, allowing students to work on their projects and labs independently of the ELVIS unit.
ELVIS provides LabVIEW-based software for interacting with the Virtual Instruments. These instruments can be modified to load Multisim data for rapid comparison of simulated and measured data.
Figure 5.4.
NI ELVIS Bode Analysis Comparing MultiSim Data