Explore Circuit Behavior Using Simulation-Driven Instruments in NI Multisim

In addition to the components and wires used to capture a circuit, NI Multisim software contains a variety of simulation-driven instruments that wire into the schematic just like you connect a real instrument on the bench. These simulation-driven instruments, like their real-world counterparts, are fully interactive so you can change their settings while running a simulation and instantly see new results.

Simulation-driven instruments help you take advantage of the full power of simulation without having to be an expert in SPICE syntax. When you press a button on an instrument, an appropriate simulation command is automatically issued and results are immediately displayed on that instrument's user interface. You can save instrument settings and simulation results with the circuit file and resize the faceplates of instruments to adjust to different screen resolutions and presentation modes.

With Multisim, you can place simulation-driven instruments from the Simulate»Instruments menu or directly from the Instruments toolbar as seen below.

Simulation-driven instruments have three distinctive views to each instrument, which allows for selection, placement, wiring, setting configuration, data visualization, and so on.

Type	Description	View
Icon	Represents an instrument in the Multisim Instruments toolbar
Symbol	Represents an instrument in a circuit Use the instrument's terminals to wire it to a circuit Double-click on an instrument's symbol to open the instrument panel
Panel	Allows the user to interact with the instrument by  Setting parameters Displaying data

You can show or hide the instrument panel by double-clicking on the instrument's symbol. The instrument panel is always drawn on top of the main workspace so that the parameters are not hidden. You can place the instrument panel wherever you wish on your desktop and resize it to account for different screen resolutions and presentation modes. When you save your circuit, the instrument panel location and hide/show status are stored with the circuit. Also, any data contained in the instrument is saved, up to a maximum size.

The three distinct types of simulation-driven instruments are Multisim instruments, LabVIEW custom VIs, and NI-ELVISmx instruments. All of these instruments offer the following key capabilities:

• Adjust settings while the simulation is running
• Rewire terminal while simulation is running
• Use multiple instances of the same instrument in one circuit
• Save instrument settings and display data with the circuit file
• Populate displayed data in the Grapher view
• Resize instrument panel to account for screen resolution or presentation mode
• Easily export displayed data in TXT, LVM, and TDM format

Multisim instruments are simulation-driven instruments that are innate in the Multisim environment. You can group them into six categories to better organize them:

Note: Pictures and icons seen in this document are reduced in size and quality. 

AC and DC Instruments

Name	Function	Icon	Symbol	Panel
Function Generator	Sine, triangular, and square wave Frequency Duty cycle Amplitude Offset
Multimeter	AC and DC Current Voltage Resistance Decibel loss
2-Channel Oscilloscope	Up to 2 channels Y and X scaling Y offset Trigger Cursor
4-Channel Oscilloscope	Up to 4 channels Y and X scaling Y offset Trigger Cursor
Wattmeter	Power measurement Power factor
IV Analyzer	Diodes PNP BJT NPN BJT PMOS NMOS
Frequency Counter	Frequency Period Pulse Rise/fall time AC or DC coupling Trigger
Bode Plotter	Frequency response Gain and phase shift Up to 10 GHz
Distortion Analyzer	Intermodulation distortion Total harmonic distortion

Digital and Logic Instruments

Name	Function	Icon	Symbol	Panel
Logic Analyzer	16 channels Cursor Data history Trigger Internal/external clock
Logic Converter	Digital circuit to truth table and Boolean expression Truth table to digital circuit Boolean expression to digital circuit
Word Generator	Cycle, burst, and step updates Hex, DEC, Boolean, and ASCII data view Timing Trigger

RF Instruments

Name	Function	Icon	Symbol	Panel
Spectrum Analyzer	Amplitude versus frequency Signal components (power and frequency) Zero, full, and custom span
Network Analyzer	Digital circuit to truth table and Boolean expression Truth table to digital circuit Boolean expression to digital circuit

Simulated Vendor Instruments

Name	Function	Icon	Symbol	Panel
Agilent Waveform Generator	Type: 33120A Reflects the behavior of the real instruments
Agilent DMM	Type: 34401A Reflects the behavior of the real instruments
Agilent Oscilloscope	Type: 54622D Reflects the behavior of the real instruments
Tektronix Oscilloscope	Type: TDS 2024 Reflects the behavior of the real instruments

Measurement Probes

Instruments Based on LabVIEW

Name	Function	Icon	Symbol	Panel
LabVIEW Microphone	Interface with your PCs sound devices Recording length Sample rate
LabVIEW Speaker	Interface with your PCs sound devices Update rate
LabVIEW Signal Analyzer	Time domain signal Auto power spectrum Running average
LabVIEW Signal Generator	Sine, triangular, square, and sawtooth Frequency Duty cycle Amplitude Offset Phase
LabVIEW Streaming Signal Generator	Sine, triangular, square, and sawtooth Frequency Duty cycle Amplitude Offset Phase Sampling rate
LabVIEW BJT Analyzer	Current-voltage characteristics of PNP or NPN BJT Device type V_CE sweep I_B sweep
LabVIEW Impedance Meter	Frequency sweep, frequency, impedance Number of points Scale type

Extend your simulation and analysis capabilities beyond the instrumentation in Multisim with the creation of custom VIs using the LabVIEW graphical development environment. VIs that you create using LabVIEW can take advantage of the full functionality of the LabVIEW development system, including data acquisition, instrument control, and mathematical analysis. For example, you can create the following kinds of VIs:

• A virtual instrument that acquires data from the real world using an NI data acquisition device or modular instrument. Multisim then uses that data as a signal source for circuit simulation.
• A virtual instrument that displays simulation data simultaneously with multiple measurements (running average and power spectrum, for example) made from that simulation data.

LabVIEW VIs can be input instruments, output instruments, or input/output instruments.

Input instruments receive simulation data for display or processing.

Output instruments generate data to use as a signal source in simulation.

Input/output instruments both receive and generate simulation data.

You can install these VIs created and customized in LabVIEW into Multisim, and they appear in the LabVIEW Instruments toolbar. For more information on building a LabVIEW VI and LabVIEW VI installation, view the Multisim Help file.

By integrating NI ELVIS and Multisim, you can correlate simulated data with real-world measurements. NI Educational Laboratory Virtual Instrumentation Suite (NI ELVIS) is an NI hardware design and prototyping platform that contains 12 of the most commonly used instruments into one integrated platform that connects to your computer through a Hi-Speed USB connection.

Inside the Multisim environment, you can access eight of these instruments. With one click of the mouse, you can switch from simulated data generated by the Multisim SPICE simulation engine and the signals acquired from the hardware. This helps engineers prototype faster and educators reinforce theory with real-world signals.

Name	Function	Icon	Symbol	Panel
NI-ELVISmx Digital Multimeter	AC voltage AC current
NI-ELVISmx Function Generator	Triangle, sine, square Up to 5 MHz Amplitude DC offset Sweep settings
NI-ELVISmx Oscilloscope	2-channel, coupling, scale volt/div Time/div Trigger Acquisition mode cursors
NI-ELVISmx Dynamic Signal Analyzer	Power spectrum and power spectral density Frequency span, resolution, window Averaging mode, weight, number of averages Trigger Units and mode to display
NI-ELVISmx Digital Reader	Acquisition mode
NI-ELVISmx Digital Writer	Pattern type Toggle, rotate, shift Generation mode Direction
NI ELVISmx Arbitrary Waveform Generator	Waveform editor Generation mode Update rate Upload waveform file  Set gain
NI-ELVISmx Variable Power Supply	+12 V/-12 V range Sweep setting