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Device Options

Click the Options | Processing Settings menu and click on the I/O Device tab or click the I/O toolbar button.  

This allows you to select a specific sound card if more than one is installed in your system.  The maximum sampling rate and precision are shown for the selected device.

The Input Device is used by the analyzer when Recording or running in the Real Time mode.  The Output Device is used by the analyzer to Playback a .WAV file or to generate a test signal using the Signal Generator Utility.

Adjust Input/Output gain - this will launch the Mixer utility provided with the operating system.  This allows you to adjust the sensitivity of the line in or mic inputs.  The output gain settings control the playback/generator volume.  Not all sound cards allow the gain/volume to be controlled.

Sound Card Driver Mode

Controls the type of driver used to access the hardware:

Standard Windows Multimedia Driver (MME) - this is the standard used by the Windows operating system and supported by the majority of sound cards.  It is very stable and provides support for a full range of sampling rates by converting the physical sampling rate of the hardware to match the desired rate.  In some cases this sampling rate conversion can introduce spectral artifacts. 

Audio Stream Input Output (ASIO) - this is a standard developed by Steinberg Media Technologies GmbH and allows direct access to the hardware.  This mode allows low level access to the sound card hardware.  The supported sampling rates are limited but there is very low "latency" involved because of the direct hardware access.  Not all sound cards provide ASIO drivers.

Note: When ASIO mode is used the signal generator cannot be started and stopped independently of the main analyzer.


When the SpectraDAQ-200 is selected as the input device the following options are available

Input Range:  This allows you to set the maximum input voltage for the A/D converters.  If you change the input range the calibration will automatically apply the correct gain to the measurement. The input range is applied to both channels.

IEPE power: You can enable IEPE power (4ma constant current) for powering microphones, accelerometers and other IEPE compliant transducers.  This eliminates the need for an external power supply and simplifies the setup and wiring.
IEPE is equivalent to ICP (a trademark of PCB Electronics).

Enable Live Monitoring: This will route the input channels to the ouput channels to allow you to listen to the signal while the analyzer is running.  This is disabled if the signal generator utility is open.  This feature only works with the ASIO driver mode.

Put SpectraDAQ-200 into low power mode when program closes: The DAQ requires significant power due to the professional quality electronics and uses USB 3.0 for this reason.  You can have the DAQ go to a low power standby mode - this will save power when using a laptop of tablet.  It will take slightly longer to startup and shutdown.

For best performance use the ASIO driver mode when the SpectraDAQ-200 hardware is selected.

See Also: SpectraDAQ-200, Calibration