Data AcQuisition And Real-Time AnalysisScope - Spectrum - Spectrogram - Signal Generator
Software for Windows
Science with your Sound Card!
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Sound Card Device Selects
This pair of controls at the top of the Start Preferences dialog allows you to select which sound card to use when you have more than one installed. If you wish to use different cards or USB devices for different Daqarta sessions, see Managing Multiple Devices. (If you only have a single card, these controls are disabled.)
There are separate controls for Output and Input devices, with the corresponding device descriptions above each control. As you scroll the device number, its description will change to match.
If you have only one Output or Input device in your system, the relevant control is disabled.
Note that changes here don't take effect until the next time Daqarta starts.
Although the Output and Input device controls are separate, you should always set them to refer to devices on the same card. Otherwise, the input and output waveforms can not be properly synchronized.
(This cumbersome dual-control method is necessitated by the fact that many sound cards now structure their inputs and outputs as separate devices, indistinguishable from physically distinct cards.)
However, it is possible to use devices on different sound cards as long as you recognize the limits. First of all, if you wish to have the composite system calibrated, you will need to run Auto-Calibrate with that system... even if you have already calibrated each card independently using its own Output and Input devices. When you calibrate, you can skip the Duplex Delay operation; the results will be meaningless here.
You can still use the Output device to create test signals with the Generator, and monitor the responses with the Input device. But since the output and input waveforms won't be time-aligned, you need to rely on the input waveforms alone for waveform averaging, or timing measurements like response latency. (That's actually the best procedure anyway, even with Output and Input on the same card.) See Full-Duplex Techniques for a discussion.
Attempting to change a disabled control via macro will result in an error message, and the macro will be aborted.
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