Error -1947 When Running Swept Sine in the Sound & Vibration ToolkitPrimary Software: LabVIEW Toolkits>>Sound and Vibration ToolsetPrimary Software Version: 4.0 Primary Software Fixed Version: N/A Secondary Software: N/A Hardware: Modular Instruments>>Dynamic Signal Acquisition and Analysis (DSA)>>PCI-4461, Modular Instruments>>Dynamic Signal Acquisition and Analysis (DSA)>>PXI-4462, Modular Instruments>>Dynamic Signal Acquisition and Analysis (DSA)>>PXI-4461, Modular Instruments>>Dynamic Signal Acquisition and Analysis (DSA)>>PCI-4462
Problem: I am getting error -1947 when running the example SVXMPL_Swept Sine FRF (DAQmx).vi (or other swept sine code). My application runs without error if I choose a smaller stop frequency for the sweep. Why am I unable to select higher values for the stop frequency, so long as they are below the Nyquist frequency? Solution: The SVT Start Swept Sine function (used in the SVXMPL_Swept Sine FRF(DAQmx) example), checks the requested stop frequency for swept sine FRF to ensure it is below the cutoff frequency of the anti-aliasing filter. This cutoff is defined as sampling rate/ 2.5. The NI-446x has a maximum sampling rate of 204.8 kS/s. This implies a maximum alias-free bandwidth of 204.8 kS/s /2.5 =81.92 kHz. Therefore if you sample at the maximum rate, although the Nyquist frequency is 204.8 kHz/2=102.4 kHz, you can select a stop frequency up to 81.92 kHz. Related Links: Attachments:
Report Date: 04/01/2006 Last Updated: 03/12/2007 Document ID: 3W0JOBMO |
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