External 10MHz Reference Detection

[MHR]

Hi Everyone

I need to find a way to ascertain that I have a working external 10MHz reference attached to my PXI card frame and my system is running on it.

Any methods or examples if this can be done would be appreciated.

Thanks

Michelle

[MahdiehG]

Hi Michelle,

Thanks for your post. Please can you give me more information about your system set up. For instance:

- Which chassis are you using?

- How are you routing your external reference?

Many thanks,

[MHR]

Hi Mahdieh G

We are using two PXI 1045 card frames, one dedicated to logic and audio, the other to RF. Both cardframes have a 10MHz external ref wired in parallel which is driven from an off air standard. All our ATE systems use this standard via a distribution system.

Hope that helps

Michelle

[MahdiehG]

Hi Michelle,

I have done a lot of research into this and also spoken to our headquarters in the US. The conclusion is that an external clock wired into PXI_CLK10 IN overrides the 10MHz backplane clock. This is done in hardware and cannot be monitored using any driver calls hence there are no LabVIEW VIs that you can use.  

Reading the signal on the PXI_CLK10 OUT will display the current reference clock however this will have a slight delay since it needs to be transfered from the input to the output.

I hope this answers your question.

Kind regards,

[MHR]

Thats what I suspected, other than T'ing of some of the reference input and measuring it, it looks like a non-starter

Michelle