How do I Phase Lock Loop (PLL) Multiple NI-DAQmx Tasks on the Same Device?Hardware: Multifunction DAQ (MIO)>>M Series
Problem: I have multiple NI-DAQmx tasks that I want to phase lock loop (PLL) to an external clock, but when I define a reference clock for one of my tasks I get Error -89137: Specified route cannot be satisfied. Solution: M-series cards have the ability to PLL their internal 80MHz sample clock source to an external reference clock. All tasks on the board share the same circuitry for the sample clock source so all tasks must use the same reference clock or sample clock source. The problem in this case is that only one task has been set to use the reference clock, and the other task still has its default behavior using the internal clock. This produces an error since the reference circuitry has already been set to the reference clock. To avoid this error, both tasks must be explicitly set to use the reference clock. In LabVIEW, you can do this by using a property node on both tasks. As the figure below shows, we need to use the RefClk.Rate and RefClk.Src property nodes.
Related Links: KnowledgeBase 3PSGM42W: What Is a Phase-Locked Loop (PLL)? Developer Zone Tutorial: Phase-Locked Loops Attachments:  - reference clock.JPG
Report Date: 01/02/2007 Last Updated: 01/09/2009 Document ID: 4519AHT3 |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
