PLL to External Reference Clock with NI Scopes Primary Software: Driver Software>>NI-SCOPEPrimary Software Version: 3.0 Primary Software Fixed Version: N/A Secondary Software: N/A Hardware: Modular Instruments>>High-Speed Digitizers (Scopes)
Problem: I am trying to PLL to an external reference clock with my National Instruments Scope card. I have configured my reference clock for an external input using the NI Scope Configure Clock VI in LabVIEW, yet when I run the program I receive an "Error -1074115830 occurred at niScope Initiate Acquisition.vi" The specifications sheet state that the reference clock must have a frequency of 1MHz to 20MHz in 1MHz increments, with an accuracy to 50ppm, and my clock source fits all those requirements. I am using a reference clock that is at a rate that is not 10MHz. What step(s) am I missing? Solution: When using an external reference clock at a frequency besides the 10MHz default expected value, you must explicitly specify the reference clock rate as well. Instead of using the niScope Configure Clock VI, try using the niScope property node to access the Reference Clock Source and Reference Clock Rate properties (see screenshot). These properties are found under the Clocking submenu. First, specify the source ("VAL_CLK_IN" for external input; check context help for other source values), then specify the expected reference clock rate (in Hz). You should then be able to PLL to an external reference clock with a rate other than 10MHz. Related Links: NI High-Speed Digitizers Help Attachments:
Report Date: 09/26/2006 Last Updated: 10/18/2006 Document ID: 41P9C1JQ |
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