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!

Main Tone Frequency

Controls: Gen Dlg >> Stream >> Tone Freq >> Main Freq
Macro: ToneFreq

Controls the frequency of the waveform for the stream.

Frequency may be set to any value up to the Nyquist frequency, which is half the actual sample rate.

This control is present in the main Tone Frequency dialog, and also in the AM, FM, and PM modulator dialogs for convenience. It is not available when the main Wave is one of the Noise types.

The maximum frequency resolution is limited by the effective sample rate:

 
Resolution (Hz)  =  Sample Rate  / (65536 * 8192)
 

For a sample rate of 48000 Hz, the resolution is thus 0.000089 Hz.

The actual frequency entry process is controlled by the Step Mode shown on the button below the frequency control. This defaults to Step Direct. If you click on this button to open the Step Mode dialog, and enter 0 in the value under Step Direct (or under Step Hertz if selected), the step value will show as 0.00001 Hz. Daqarta interprets this to allow scrolling of the Tone Frequency at the finest (89 ppm) resolution.

You may want 6 or more decimal places for this. By default, all Generator frequency controls show 5 digits after the decimal. You can adjust this between 0 and 9 using the Frequency Places control in the Step Mode dialog.

Step Modes allow you to step to only certain frequencies that are Step Hertz apart, or to exact spectral Lines, or by Octave or musical steps (or fractions or multiples).

When Play Wave type is active, the Freq control changes to Rate. The Play Rate control allows Rate to be set relative to the absolute rate (Abs), as recorded originally, or relative to the current sample rate (Rel).

Note that when Freq is set to 0, the output is a constant level controlled by the Phase setting; at a Phase of 90 degrees the output of a Sine wave is a constant 100%, for example. This can be useful when used with Burst or Phase Modulation to modulate another stream.


Macro Notes:

L.1.ToneFreq=1k sets Left Stream 1 Tone Frequency to 1000 hertz.

L.1.ToneFreq=>1 increments the frequency to the next higher Frequency Entry Step, while L.1.ToneFreq=>-1 decrements to the next lower step. Only +/-1 step is accepted.

Note that the ToneFreq command will change the indicated frequency value even if that stream is using a Noise-type Wave that doesn't allow normal user access to the Frequency dialog. In that case, there will be no change to the output signal until a non-noise Wave type is selected.


See also Main Phase, Tone Frequency Dialog, Waveform Stream Controls.


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