Multi-Instrument Turn a PC into Multiple Virtual Instruments!
Instroduction
Multi-Instrument is a powerful multi-function virtual instrument software. It supports a variety of hardware ranging from sound
cards which are available in almost all computers to proprietary ADC and DAC hardware such as NI DAQmx cards, VT DSO, VT
RTA, VT IEPE, VT CAMP and so on. It consists of an oscilloscope, a spectrum analyzer, a signal generator, a multimeter, a
spectrum 3D plot, a data logger, a Vibrometer, a LCR meter and a device test plan, all of which can run simultaneously and in
real time. It has been widely used in education, scientific research, audio & acoustic engineering, electronic engineering,
vibration analysis, medical diagnosis, musical instrument inspection, etc. The software can be downloaded from:
www.virtins.com/MIsetup.exe for a 21-day fully functional FREE trial, with your computer sound card as the ADC and DAC
devices.
Oscilloscope
View Type
Waveform for Ch.A and Ch.B
Waveform for Ch.A + Ch.B
Waveform for Ch.A – Ch.B
Waveform for Ch.A × Ch.B
Lissajous Plot
Mixed Signal Display
Inter-frame Processing
It is performed among a specified number of adjacent
data frames in time domain. It includes:
Linear Averaging (2~200 frames, forever) (Mixed Signal Display)
Exponential Averaging
Demodulation Interpolation in Curve Plotting
AM, FM, PM Linear / SINC
Digital Filtering
FFT (Low Pass, High Pass, Band Pass, Band Stop,
Arbitrary)
FIR (Low Pass, High Pass, Band Pass, Band Stop,
Arbitrary)
IIR (Arbitrary)
DC Removal and Half/Full Wave Rectification
Record Mode
This is one of the streaming modes. Under this mode, (Sine Wave Frequency Sweep in Rainbow Persistence Mode)
the acquired data will be written to the hard disk
continuously in wave file format. Meanwhile, data analysis and display will still be performed in order to monitor the input signal
in real time.
Roll Mode
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Multi-Instrument Turn a PC into Multiple Virtual Instruments!
This is one of the streaming modes. Under this mode, the oscilloscope frame is split into many segments with the length of
each segment equal to the Roll Width. The data displayed in the oscilloscope will shift left at a step of one Roll Width each time
when a new segment of data arrives. The newly arrived data will be shown in the right most portion of the graph. Roll Mode
can be used if the sweep time of the oscilloscope is too long (e.g. greater than 1 s) to avoid long time waiting for screen update.
Persistence Mode
This mode allows hundreds of consecutive waveforms to be superimposed / drawn in the oscilloscope window in three ways:
Phosphorescent, Rainbow, Equivalent Time Sampling. The former two are useful to capture intermittent and unstable events
hidden in a series of repeated normal events, while the latter one can be used to increase the displayed samples per cycle when
the real time samples per cycle is insufficient to render the actual waveform properly, provided that the signal itself is repetitive.
Spectrum Analyzer
View Type
Amplitude / Power Spectrum
Phase Spectrum
Auto Correlation Function
Cross Correlation Function
Coherence / Non Coherence Function
Transfer Function (Bode Plot) / Impedance Analyzer
Impulse Response
FFT Size vs Record Length
If the FFT size is greater than the record length of a
data frame, then zeros will be padded at the end of the (Sine Wave Amplitude Sweep in Rainbow Persistence Mode)
data frame during FFT computation.
If the FFT size is less than the record length of a data
frame, then the data frame will be split into different
segments with the size of each segment equal to the
FFT size. The last segment of data will be dropped if its
size is not equal to the FFT size. The final result will be
obtained by averaging the FFT results from all segments.
Window Function Window Overlap
55 window functions 0%~99%
Processing
Intra-Frame Processing (Frequency Response Measurement using white noise and
It is performed within a data frame in frequency domain. narrow band spectrum analysis)
It includes:
Frequency Compensation
Frequency Weighting (A, B, C, ITU-R 468)
Remove DC
Smoothing via moving average
Inter-Frame Processing
It is performed among a specified number of adjacent
data frames in frequency domain. It includes:
Peak Hold (2~200 frames, forever)
Linear Averaging (2~200 frames, forever)
Exponential Averaging
(Frequency Response Measurement using pink noise and octave
Parameter Measurement band analysis)
It is performed after the Intra-Frame and Inter-Frame
processes. Parameters that can be measured are:
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Multi-Instrument Turn a PC into Multiple Virtual Instruments!
THD, THD+N, SINAD, SNR, Noise Level, in a specified frequency band. The highest order of harmonics for THD calculation
can be specified.
IMD (SMPTE/DIN, CCIF…)
Bandwidth
Crosstalk
Harmonics (including frequencies, amplitudes & phases)
Energy in user defined frequency bands
Peaks, SFDR
Sound Loudness, Loudness Level & Sharpness
Wow & Flutter (weighted or not weighted)
Non-Coherent Distortion & Noises
GedLee Metric for Perception based Nonlinear Distortion
X Scaling
Linear
Log
Octave 1/1, 1/3, 1/6, 1/12, 1/24, 1/48, 1/96 (Measurement of THD, THD+N, SNR, SINAD, ENOB)
Y Scaling
Relative Mode
Linear
dBr
Absolute Mode
Vrms
dBV
dBu
dBSPL
dBFS
Signal Generator
(Measurement of SMPTE IMD)
Waveform
Sine
Rectangle (with adjustable duty cycle)
Triangle
Saw Tooth
White Noise
Pink Noise
Multi-Tones
Arbitrary waveform
MLS, with adjustable length (127~16777215)
DTMF
Unit Impulse
Unit Step
Musical Scale
Wave File
(Impact Test by detecting multiple frequency peaks)
Frequency/Amplitue Sweep
Linear
Log
Burst Generation
A periodic on/off mask can be configured to mask on/off the output signal. This feature
can be used to generate burst-like signal. An option is provided to phase lock each burst.
Modulation DDS/Stream Mode
AM, FM, PM Both are supported.
(Burst Sine)
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Multi-Instrument Turn a PC into Multiple Virtual Instruments!
Loopback Mode
Loopback is generally used to feed the signal output by
the signal generator to the input of the oscilloscope, so
that the output signal can be displayed and analyzed in
real time.
Hardwired Loopback
It is established via an external cable, to loopback the
output signal to the input of the oscilloscope.
Mixer Level Loopback (sound card only)
It is established at the sound card mixer level through
the configuration under Windows Control Panel.
Software Level Loopback
No Loopback
iA=oA, iB=oB
iA=oA, iB=oA
iB=oA
(Measurement of Transfer Function (Bode Plot) using Dual FFT)
Sync. No Loopback
Sync. iB=oA
Sync. iB<--oA
Multimeter
View Type
RMS
dBV
dBu
dBSPL
dB(A)
dB(B)
dB(C)
Frequency Counter
RPM (Revolutions Per Minute)
Counter
Duty Cycle
F/V (Freq. Volt. Conversion)
Cycle RMS
(Maximum Length Sequence (MLS) in narrow band spectral analysis)
Cycle Mean
Pulse Width
The latter eight involve a pulse counting process, and the software allows
you to configure the counter’s trigger level, trigger hysteresis and frequency
dividing ratio.
Spectrum 3D Plot
It is used to trace the spectrum variation with time. Two types of plots are
provided:
Waterfall Plot
Spectrogram (Spectrogram)
with adjustable tilt angle of T axis, adjustable height of Y axis, and selectable color palettes.
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Multi-Instrument Turn a PC into Multiple Virtual Instruments!
(Waterfall Plot) (Waterfall Plot with a 3D Cursor Reader)
Data Logger
It provides long time data logging function for 196
derived data points and 16 user defined data points,
including RMS value, peak frequency, sound pressure
level, RPM, THD, etc. Up to eight data logger windows
can be opened and each window can trace up to 8
variables. The logged data files can be reloaded into the
data logger for review.
Three logging methods are supported:
Fastest
Take one record whenever new data are available
Time Interval
Take one record whenever new data are available and
the specified time duration has elapsed since the last
update.
(Data Logger)
Update Threshold
Take one record whenever new data are available and the change compared with the last update exceeds the specified
update threshold.
LCR Meter
It is one of the dedicated Device Test Plans. It is used
to measure the value of an inductor, a capacitor or a
resistor, or the impedance of a network of them.
Two types of external connections are supported:
Serial connection for high impedance measurement
Parallel connection for low impedance measurement
Device Test Plan (LCR Meter)
It provides a mechanism to configure and conduct your own device test steps. It takes the advantage of the hardware’s
capability of simultaneous input and output, to generate a stimulus to the Device Under Test (DUT) and acquire the response
from that device at the same time. Different stimuli can be generated and the response can be analyzed in different ways. The
DUT can be marked as Pass or Fail after a sequence of test steps.
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Multi-Instrument Turn a PC into Multiple Virtual Instruments!
Device Test Plan supports 23 instructions with corresponding parameters. Test results (e.g. Gain vs Frequency, Phase vs
Frequency, etc.) can be plotted in up to 8 X-Y plots in real time.
(Pass / Fail Test) (Gain and Phase Plot using frequency stepped sine)
(THD, THD+N, SNR, Magnitude Response vs Frequency) (Crosstalk vs Frequency)
Vibrometer
It can perform waveform conversion among acceleration,
velocity and displacement when acceleration, velocity or
displacement sensors are used. The RMS, Peak/PP, Crest
Factor values for acceleration, velocity, displacement are also
displayed.
DDP Viewer
It is used to display the value of a Derived Data Point (DDP) in
a dedicated window with a bigger font size. It is also possible to specify the DDP’s high-high, high, low, low-low limits for
alarming and the number of decimal places for display. Up to 16 DDP viewers can be opened. These DDP viewers can also be
used to define and display User Defined Data Points (UDDP). A UDDP can be expressed as a function of DDPs and earlier-
updated UDDPs. The mathematical expression may consist of constants, DDPs, UDDPs, mathematical operators, and
mathematical functions. A DDP Array Viewer can be launched from the DDP Viewer, which can be used to display a DDP array
or a combination of DDP arrays, such as a harmonic analysis report consisting of arrays of harmonics frequencies, amplitudes
and phases.
General Functions
Sensor Sensitivity
The acquired data can be rescaled according to the sensor sensitivity configured by the user so that the displayed data are
expressed in engineering unit corresponding to the physical quantity sensed by the sensors. This is very different from a
conventional oscilloscope whereby only voltage can be displayed.
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Multi-Instrument Turn a PC into Multiple Virtual Instruments!
Graph Operation
Zooming and Scrolling is supported in all graphs, allowing you to investigate the fine details of the data. This is very important
when a large amount of data are displayed in one screen. A cursor reader is provided in each graph to show the x and y
readings of the actual measurement point. For Spectrum 3D Plot, the cursor reader supports the readout of x, y, t values of the
actual measurement point. Two markers are provided in each graph to get the x and y readings of the actual measurement
points nearest (in horizontal direction) to the points of the mouse clicks. Five chart types are supported: Line, Scatter, Column,
Bar, Step. Line width and colors of the graph are configurable. Options are provided to either display all data points (slow) or
only display one data points per vertical raster line (fast). The data in any graph can be copied into the clipboard as text and
later paste into other software such as Microsoft Excel for further analysis. The image of the graph can be copied into the
clipboard as Bitmap image and later paste into other software such as Microsoft Word.
Reference Curves
Up to five reference curves can be set for each channel in each graph. The reference curve can be configured by either copying
the current curve, or loading a properly formatted text file or a previously saved reference file from the hard disk.
File Import and Export
The collected frame of data can be saved as a wave file (*.wav) or exported as a text file (*.txt). All analysis results can be
exported as text files (*.txt). All graphs can be exported as bitmap files (*.bmp) or printed out directly. A long wave file can be
imported frame by frame either manually or automatically. Wave files with PCM format or properly formatted text file can be
imported for analysis. The signal generated by the signal generator can be saved as a wave file or a text file for a given
duration of up to 1000 seconds.
Data Merging and Extraction
Combining data from individual channels of different wave files, and extracting part of data from a wave file are supported.
Save and Load Panel Setting
You can save your preferred instrument panel setting either as default or as a customized panel setting for later use.
Controls/Options Enabling and Disabling
Graphical User Interface items such as menu items, button, combo box, edit box, radio box, check box are enabled/disabled
based on context, so as to void any mis-understanding and mis-operation.
Multilingual User Interface
It supports Multilingual User Interface under Windows XP, Vista, 7, 8 and 10. Supported languages are English, French, German,
Italian, Portuguese, Spanish, Russian, Simplified Chinese, Traditional Chinese, Japanese and Korean.
Supported Hardware
Sound Card
The software can be used with a sound card and a microphone to measure and analyze sounds. To measure electric signal, the
following dedicated sound card oscilloscope probe kit can be used.
P601PC Probe Kit
Maximum Allowable Input Voltage: ±24 V
Built-in input protection circuit ensures its output to be less than 3V at all time,
provided the input voltage is within the allowable range.
Three switchable attenuation positions: 1, 2, 3, with input impedance equal to 1kΩ +
Zsc, 201kΩ + Zsc, 10.001MΩ + Zsc, respectively. Note that Zsc is the sound card input
impedance which ranges from 600Ω to 50kΩ typically.
Its back end is a RCA plug and can be connected to an ordinary sound card through a
stereo-to-2RCA converter or a mono-to-1RCA converter. No converter is required for those sound cards that have RCA jacks
for input and output.
VT RTA
The software supports VT RTA series. A Real Time Analyzer (RTA) is usually used to measure in real time the frequency
response of an audio system within the confinement of an environment, such as auditoriums, home theatres and cars, taking
into account the frequency response of the audio system itself as well as all the environmental effects such as resonance and
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Multi-Instrument Turn a PC into Multiple Virtual Instruments!
constructive and destructive interference. One can then adjust the equalizer to make an inversed
frequency response such that the combined frequency response is flat or aligned to the preference
of the audiences.
VT DSO
The software supports VT DSO series. A Digital Storage Oscilloscope (DSO) is used to acquire,
process and analyze electronic signals. Virtins Technology offers a comprehensive list of DSOs as
follows.
Model ADC (Oscilloscope) DI DAC (Signal Generator)
AI Band Max. Bit Buffer* Full EXT Full AO Band Max. Bit DDS Full
Width Sampling Depth (Bytes) Scale as DI Scale Width Sampling Depth Buffer Scale
(MHz) (MSPS) (Bits) Range Range (MHz) (MSPS) (Bits) *(Byes) Range
(V) (V) (V)
2810 2 40 100 8~16 40000 ±0.01 Y ±20 1 0.15 3.125 10 2048 ±2
~
±50
2810E 2 40 100 8~16 40000 ±0.01 Y ±20 1 60 200 10 2048 ±2
~
±50
2810R 2 40 100 8~16 40000 ±0.05
~
±50
2820 2 80 200 8~16 40000 ±0.01 Y ±20 1 0.15 3.125 10 2048 ±2
~
±50
2820E 2 80 200 8~16 40000 ±0.01 Y ±20 1 60 200 10 2048 ±2
~
±50
2820R 2 80 200 8~16 40000 ±0.05
~
±50
2A10 2 40 100 10~16 40000 ±0.01 Y ±20 1 0.15 3.125 12 2048 ±2
~
±50
2A10E 2 40 100 10~16 40000 ±0.01 Y ±20 1 60 200 12 2048 ±2
~
±50
2A10R 2 40 100 10~16 40000 ±0.05
~
±50
2A20 2 80 200 10~16 40000 ±0.01 Y ±20 1 0.15 3.125 12 2048 ±2
~
±50
2A20E 2 80 200 10~16 40000 ±0.01 Y ±20 1 60 200 12 2048 ±2
~
±50
2A20R 2 80 200 10~16 40000 ±0.05
~
±50
2840E 2 150 400 8~16 40000 ±0.01 Y ±20 1 60 200 10 2048 ±2
~
±50
2840R 2 150 400 8~16 40000 ±0.05
~
±50
2A40E 2 150 400 10~16 40000 ±0.01 Y ±20 1 60 200 12 2048 ±2
~
±50
2A40R 2 150 400 10~16 40000 ±0.05
~
±50
NI DAQmx Cards
The software supports NI DAQmx cards.
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