Import and Export Clock Signal in a HSDIO card

Updated Jun 5, 2018

Reported In


  • PXI-6541



Issue Details

I need to synchronize the output sample clock and the input sample clock of a PXI-6541 (HSDIO) to the output clock of a PXIe-6535 (DAQ). How can I import a clock to do that?


Visit NI Digital Waveform Generator/Analyzer Help to get a complete information for your specific HSDIO card under Devices >> Your Card´s Family >> Hardware Architecture >> Clocking.


i.e for the PXI-6541 you can observe that CLK IN, PXI_STAR line, STROBE and PXI_CLK10 can be imported to produce the clock signal.

By checking in section Clock Sourcers Summary you can verify if the clock signal can be routed to both Acquisition and Generation:



Visit NI Digital Waveform Generator/Analyzer Help and go to Devices >> Your Card´s Family >> Hardware Architecture >> Clocking >> Exporting a Clock you can observe which options you have for exporting a HSDIO clock signal.

i.e with a PXI-6541 card:

For more informationa about synchronization methods take a look at HSDIO Generation and Acquisition Synchronization linked below.

Additional Information

Each HSDIO board has a separate timing engine for acquisition and generation tasks.  What this means is that the generation and acquisition tasks can make independent use of either the On Board Clock, External Clock, or Reference Clock. For example, the generation timing engine can run off the on board clock frequency generated by its internal oscillator, and the acquisition timing engine can run at a different frequency based on an external clock. They do not have to have any timing relationships between the two, although it is common and encouraged to phase align these signals.


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