Portable Multi-Instrument 3.6




Multi-Instrument portable is a powerful PC based 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, Virtins Technology’s Digital Storage Oscilloscopes (VT DSO), Virtins Technology’s Real Time Analyzers (RTA) and so on. It consists of an oscilloscope, spectrum analyzer, signal generator, multimeter and five add-on software modules: data logger, spectrum 3D Plot, vibrometer, LCR meter and device test plan, all of which can run simultaneously and in real time. It has been widely used in education and training, scientific research, audio and acoustic engineering, electronic engineering, vibration analysis, medical diagnosis, musical instrument inspection, etc.

What can a Multi-Instrument system do?

separate waveforms, waveform addition, subtraction and multiplication, Lissajous Pattern, mixed signal display, long-time signal recording (streaming mode), pre-configured or arbitrary digital filters (FFT, FIR, IIR), digital persistence display, equivalent time sampling, roll mode, etc..

Spectrum Analyzer
amplitude spectrum, octave analysis (1/1, 1/3, 1/6, 1/12, 1/24, 1/48, 1/96), frequency compensation, frequency weighting (A, B, C, ITU-R 468), peak hold, linear / exponential average, measurement of THD, THD+N, SNR, SINAD, Noise Level, IMD, Bandwidth, Crosstalk, peaks, harmonics, phase spectrum, auto / cross correlation, coherence function, transfer function (Bode plot, gain and phase plot, or frequency response), impulse response. Support 55 window functions and window overlap.

Signal Generator
function / multitone / arbitrary waveform / burst tone / MLS / DTMF / musical scale / white noise / pink noise generation, frequency/amplitude sweep, fade in/out, wave file replaying. Support both streaming mode and DDS mode.

voltmeter, sound pressure level meter(dB, dBA, dBB, dBC), frequency counter, RPM meter, counter, duty cycle meter, F/V converter, cycle mean/RMS

waveform conversion among acceleration, velocity and displacement, when the raw data are acquired from acceleration, velocity or displacement  sensors. This function is designed specially for vibration analysis.

Spectrum 3D Plot
waterfall and spectrogram.

Data Logger
long time data logging for 151 derived data points (DDP) and 16 user defined data points (UDDP), including RMS values, peak frequencies, sound pressure levels, RPM, THD, etc. Up to eight data logger windows can be opened and each window can trace up to 8 variables.

LCR meter
measure the value of an inductor, capacitor or resistor, or the impedance of a network of them.

Device Test Plan
It provides a mechanism to configure and conduct the user’s own device test steps. It takes the advantage of the sound card’s (or other ADC/DAC device’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.

DDP Viewer
It is used to display the value of a Derived Data Point (DDP) in a dedicated window with bigger font size. It is also possible to specify the DDP’s high-hgih, 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.

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.

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.