FPGA and Acquisition module Clock. Synchronization issue

[DavideSignorino]

Hello All,
I have a C-Rio 9082 with NI 9225 acquisition module for Voltage, NI 9227 acquisition module for Current and NI 9467 for GPS Synchronization. How can I get the Time Stamps of each sample acquired from NI 9225 and not only for PPS? Is there a way to use the same clock for FPGA and the acquisition modules?
In image "1" I wait for gps synchronization and save with local variables the value of a Timer and the value of Numeber of Samples between 2 PPS. In image "2" I start the acquisition but this use onboard module clock and not the fpga clock so I cannot go up to the time when samples were acquired.
(I can use the same clock for acquisition modules but not the same of CRio)

[Lamber_86]

Hello,

have you tried with FPGA Timekeeper Library?

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P70iSAC

[DavideSignorino]

Hello Lamber_86,
Yes I have, but there's no connection between acquisition modules clock and gps module clock. I think that  FPGA Timekeeper Library uses the FPGA clock for getting the timestamp and I can use it to know, in nanoseconds, when the sample was read but not when it was acquired.

[xl600]

I’m not familiar with cRIO, but on pxie fgpa modules the fgpa timekeeper IS the fgpa clock.  It’s the only way to have a clock in your fpga directly.  Also on pxie, acquisition modules do not have a clock.  The system clock of the controller is what is used for timestamping and creation of any t0 waveform values.  How exactly precise t0 values are obtained, I’m not sure (does anyone know of a white paper on this?).

the gps module and NI Timesync should be keeping the gps time and sysclk time in close alignment.  An rt loop should be used to update the fgpa timekeeper using the sysclk.  Therefore, you are not syncing fgpa to gps directly.  Some delta will exist that needs to be characterized.

PPS May be the best way for direct sync