hi dale, my guess is that your system clocking works as follows: the sample clock for the KatADC is sent into the ADC via an SMA coax cable from an external synthesizer. the KatADC then sends that clock (actually the sample_clock / 2^k) to the FPGA via zdoc. the FPGA uses that zdoc clock for the correlator DSP logic, so the correlator is running synchronously with the ADC samples. the QDR is likely also running off the same clock as the correlator DSP, so it's also synchronous with the ADC samples.
it would be interesting to look at the QDR test software, and see if it's using the same clock rate as your FPGA correlator clock. if the QDR test is using a higher clock rate than you need, the roach2 QDR might be fine for your correlator. if there is a way to adjust the correlator test's clock rate, you could see at what clock rate the QDR if fails, and if you have plenty of margin, it's probably fine to use those roach boards. best wishes, dan On Tue, Sep 22, 2026 at 8:14 AM Dale Gary <[email protected]> wrote: > Thanks Jack and Jonathan for the replies. We have the clock signal coming > into the KatADC on zdok1 (the second one). I wonder if there are jumpers on > the board that set the clock source and may be misconfigured? I have a dim > recollection of that sort of issue. > > Regards, > Dale > > Sent from my iPhone > > On Sep 22, 2026, at 3:32 AM, Jack Hickish <[email protected]> wrote: > > > Hi Dale, > > As far as I'm aware there are no special settings needed for QDR - > everything is baked into the firmware. Does the failure give any useful > information? > Has the new board passed its factory QDR tests at digicom? > > Cheers > Jack > > On Mon, 21 Sept 2026 at 23:38, Dale Gary <[email protected]> wrote: > >> Hi All, >> >> We've been running our EOVSA correlator for nearly a decade now, but one >> of our ROACH2 boards has finally failed. We replaced it with another >> ROACH2 and installed the same KatADCs moved from the failed ROACH2. >> However, the new ROACH2 board fails its QDR test on all three QDRs. Are >> there some settings we have forgotten? Any other ideas? >> >> Thanks, >> Dale Gary >> >> -- >> You received this message because you are subscribed to the Google Groups >> "[email protected]" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion visit >> https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAE1wuhZ%3DKb2n%2BDJ573t%2BaBj2yZb0ExKfGLn_BAvi4Mt4_u7uoA%40mail.gmail.com >> <https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAE1wuhZ%3DKb2n%2BDJ573t%2BaBj2yZb0ExKfGLn_BAvi4Mt4_u7uoA%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > -- > You received this message because you are subscribed to the Google Groups " > [email protected]" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAG1GKSktCVbaUbUSnKAP%2BWfoFwzgzE45GuwUGu55dtR4OW%3DZMQ%40mail.gmail.com > <https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAG1GKSktCVbaUbUSnKAP%2BWfoFwzgzE45GuwUGu55dtR4OW%3DZMQ%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > -- > You received this message because you are subscribed to the Google Groups " > [email protected]" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/C2388D13-5B83-47EC-A77A-9C5868036D26%40gmail.com > <https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/C2388D13-5B83-47EC-A77A-9C5868036D26%40gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "[email protected]" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAA9jdzJxjYEgqoJ-1e_QAwKx37%3D_M5KAGMR04iHuDW7RFwtnvA%40mail.gmail.com.
