03-15-2016 07:29 AM
Hi,
I have the PCIe 6323 Card and an ultra stable 10MHz reference coming from a Maser. I converted the signal to sqarewave signal with an amplitude of 3V. I want to Phase lock the NI cards reference clock to the 10MHz external one. I connected the cable to a PFI connector. how do I program Labview so it phaselocks the Clock? When I just write it in the DAQmx-Timing (see pic in the attachments) the program does not work any more.
Thanks for helping.
Sebastian
03-16-2016 06:09 AM
Hi qport,
Why do you don’t work with the DAQmx Timing VI?
Here you have the possibility to select a sample Clock Source.
http://digital.ni.com/public.nsf/allkb/3E3D74E26B8A5B83862575CA0053E4B5
Take also a look at the example "HW-Timed Single Point Input.vi".
Open the NI Example Finder in LabVIEW at "Help --> Find Examples..."
Then Browse "Hardware Input and Output --> DAQmx -->Analog Input"
03-16-2016 11:11 AM - edited 03-16-2016 11:27 AM
Hi qport!
In order to phase lock your PCI DAQ card, you'll need to use a RTSI cable, which I see you are using in your VI.
Edit: I just noticed you're using a RTSI cable. You can find the example in LabVIEW under DAQmx -> Syncronization, but I believe you need to set the RefClk.Src in your Timing Property Node to point towards the RTSI input. The Reference Clock is what your Sample Clock is divided down from, I believe. When you set the RefClk.Src, it will PLL the clocks, and then the sample clock will be derived off the PLL clock.
However, if you are using a PXI chassis, you can phase lock clocks rather simply over the backplane.
03-17-2016 04:14 AM
Thank you for your replies,
the phase lock works now. As you proposed I set the channel with the external reference as RefClk.Src. When I measure the 20MHz Timebase freq against the 10MHz input I see that they are phase stable now.
But:
now I run into a new problem when i try to output digital (DIO0-31) and analog (AO0-4) signals triggered by a sample clock created with a counter(see pic attached). It gives me the error 89137 with the describtion :
<B>Eigenschaft: </B>RefTakt.Quelle
<B>Quellgerät: </B>Dev1
<B>Quellenanschluss: </B>None
<B>Benötigte Ressourcen belegt von</B>
<B>Task-Name: </B>_unnamedTask<0>
<B>Quellgerät: </B>Dev1
<B>Quellenanschluss: </B>RTSI7
<B>Zielgerät: </B>Dev1
<B>Zielanschluss: </B>RefClockInternal
(sorry that it is in german)
Thank you for helping