Daqarta
Data AcQuisition And Real-Time Analysis
Scope - Spectrum - Spectrogram - Signal Generator
Software for Windows
Science with your Sound Card!
The following is from the Daqarta Help system:

Features:

Oscilloscope

Spectrum Analyzer

8-Channel
Signal Generator

(Absolutely FREE!)

Spectrogram

Pitch Tracker

Pitch-to-MIDI

DaqMusiq Generator
(Free Music... Forever!)

Engine Simulator

LCR Meter

Remote Operation

DC Measurements

True RMS Voltmeter

Sound Level Meter

Frequency Counter
    Period
    Event
    Spectral Event

    Temperature
    Pressure
    MHz Frequencies

Data Logger

Waveform Averager

Histogram

Post-Stimulus Time
Histogram (PSTH)

THD Meter

IMD Meter

Precision Phase Meter

Pulse Meter

Macro System

Multi-Trace Arrays

Trigger Controls

Auto-Calibration

Spectral Peak Track

Spectrum Limit Testing

Direct-to-Disk Recording

Accessibility

Applications:

Frequency response

Distortion measurement

Speech and music

Microphone calibration

Loudspeaker test

Auditory phenomena

Musical instrument tuning

Animal sound

Evoked potentials

Rotating machinery

Automotive

Product test

Contact us about
your application!

Daqarta Screen Tour

When you start Daqarta, the central trace area is a black starfield with green text showing the Daqarta name, version, copyright date, and Website address. A message above the trace area says "Generator button toggles sound output."

Hit SHIFT + Home (for example) to see the basic screen without actually toggling anything on:

The title bar above the main window defaults to "Daqarta For Windows". If you open a file, the file name will also be shown here.

The menu bar just below the title holds File, Edit, Calibration, Options, and Help selections, each of which opens a submenu with multiple options.

Just below the menu bar is a toolbar with buttons labeled Averager, DD / Open (which changes to DDisk when live input or output signals are active), Generator, Input, Sgram/PT, Spectrum, Trigger, X-Axis, and Zero that toggle main Daqarta features.

Below each of these labeled buttons is a thin unlabeled button which opens a repositionable control dialog for that feature, such as the Generator control dialog shown here on the right side of the screen. It appears by default when you start Daqarta.

The toolbar toggle buttons may also be activated by hitting ALT plus the indicated letter, such as ALT+A to start an average, or ALT+M to view a Spectrogram / Pitch Track (Sgram/PT). The associated control dialog may be opened via CTRL plus the same letter. When you open a control dialog, it replaces any other dialog that may have been visible; you can't have more than one such dialog open at the same time.

Just below the Averager button is the Total Frames Counter, which counts the number of averager frames accumulated.

In the upper center of the main window is a line of text reminding you to "Right-click any control for Context Help." If you are wondering about anything you see, anywhere in Daqarta, right-clicking it will bring up its specific Help topic. (There are more than 600 such topics in the Help system, plus hundreds more that they link to... over 950 total.)

Below that line is a blank line, then a long window showing "440 Hz Sine (default)". This is title or description of the default Generator setup file Setup.GEN that is loaded automatically at startup. The Setup.GEN name is not shown, but if you load another setup manually the file name will appear on the blank line above this. (You can save any setup as Setup.GEN for auto-loading.)

Continuing the tour, let's look at a sample screen of Daqarta in action. The image below shows Daqarta generating two output waveforms with the Generator, and monitoring them on the sound card Input via a loopback cable from the sound card Line Out to Line In.

Note that the Generator and Input buttons are active in the toolbar, and that the former DD / Open button is now DDisk for continuous Direct-to-Disk recording.

The Generator traces show the raw output signals that are sent to the sound card. (A "trace" is the plotted line representing each signal channel.) The Left output (green) is a 100 Hz full-scale (100% Level) sine wave, and the Right (violet) is a 100 Hz triangle at 180 degrees phase. This information was entered into the Generator title above the trace area for reference.

The Left Input (yellow) and Right (red) traces show the sound card responses to these two signals. The horizontal positions of the input traces relative to the outputs have been shifted due to lack of Auto-Calibration, which corrects for the internal "Duplex Delay" of the sound card. There are also phase shifts and triangle shape change due to sound card output and input coupling capacitances acting like high-pass filters. These observations were entered into the Notes area below the trace area, which will be included when saving a .DQA data file.

The Trigger button on the toolbar is active in order to synchronize the traces with the rising zero-crossing of the Left Out waveform, as set in the Trigger control dialog. A small cursor-colored square is shown in the upper right corner of the trace area on alternating trace updates, so you can tell that the trace is "live" even with a waveform such as this one that repeats exactly on each update. At the default 10 msec update interval, on a signal with frequent Trigger events, this may merely seem to flicker.

The horizontal axis shows the time relative to the start of the trigger event. The trigger control dialog allows you to move this around via its Trigger Delay control.

The X-Axis button is active to eXpand the horizontal axis of the display. Its control dialog has Max and Min controls which were set to show slighty more than the first 10 msec, which covers one full cycle of the 100 Hz waves. Read the X-Axis eXpand topic for other ways to control this axis.

The vertical axis of the trace area shows +/-1000 mV, but the "Uncal" label above the axis means that any measurements are at best only crude approximations until you calibrate the sound card. You can change the trace magnification via the small up/down arrows above the axis, or by using the PgUp or PgDn keys, or by dragging the axis itself. Note that the ranges for different display modes are always kept separate, so changing the waveform range has no effect on the spectrum.

Below the Y-axis labels are left-right arrow buttons which can be used to adjust the low end of the X-axis expansion. A similar pair at the right side of the X-Axis control the high end. But you can just put the mouse near either end of the axis and drag it. Specific end values can be entered from the X-Axis control dialog.

Two light blue vertical lines, one solid and one dotted, are superimposed on the trace area as cursors. They can be dragged horizontally to any position on the trace area. The cursor readout windows below the trace area show the X and Y values where the cursors intersect the Left Out waveform. The small green buttons control the trace the cursors apply to, and each can be clicked to show any of the visible traces.

The right-most upper readout window shows that the time difference between the two cursor positions is 5.00000 msec. (Note that the 'm' is inside the window, and the 'sec' is just outside.)

The Delta (triangle) symbol adjacent to the window below indicates that it shows the difference between the two waveform values (dotted minus solid).

You can click the Delta to Sigma mode (like a bent 'E'), in which case it will show the Root Mean Square (RMS) of the waveform between and including the cursor positions. (It always uses the trace indicated by the solid cursor, even if the dotted cursor is set to another trace color.)

To the left of the readouts are four channel display buttons. When you toggle Generator or Input on, all active channels are displayed by default, and the relevant display button is shown with its associated trace color. You can toggle off any channel you don't want to see at the moment by clicking on its display button, which will go to gray until you toggle it back on. This only affects the trace display; Generator channels still send data to the outputs, and the Averager still accumulates data, for example. If a channel is inactive in its control menu, its display select button is grayed and disabled.

The Pause button (which you can also toggle with ALT+P) allows pausing the display if it is changing too rapidly to view. This pauses the display only; it has no effect on the input or output signal. The Averager (except in Exponential modes) will activate Pause automatically when it has accumulated the requested number of frames.

The Notes button opens a larger Notes window to allow viewing of multiple lines of text without scrolling. The Font button below it affects both the Notes displays.

Below the Notes area are 6 Label windows that were originally marked "Label 1" through "Label 6", and below them 6 corresponding Field windows. You can enter anything you want into these windows, and it will be included when you save a .DQA data file. The image shows a typical use for recording experiment parameters, with "Freq, Hz" replacing the original Label 1, and "100" in the field below it. CTRL+ALT+D can be used to enter the date, and CTRL+ALT+T to enter the time. Macros that automate your experiment can also enter labels and field values automatically.

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