Hi It's the whole "unlock and relock thing that I was trying to get around. In any PLL, the VCXO / VCO will need to pull a bit further than the lock range, just to get things lined up. Testing this sort of thing can be a pain.
Bob On Jan 30, 2012, at 2:20 AM, Javier Herrero wrote: > Hello, > > Also I expect that the range would be somewhat limited by the unit software, > since the control word is 32-bit, same as the DDS program word with, and I > don't think that the little thing would enable to program the DDS from zero > to 32-bit. In any case, my idea was first to only monitor the DDS word (at > serial port) and serial port offset message limits, and also to test in that > way the lock range of the 5680A - this can be a bit tedious since when I > programmed a 10Hz offset, the unit unlocked ant took several seconds to lock > again. > > Regards, > > Javier > > El 29/01/2012 21:41, Bob Camp escribió: >> Hi >> >> If you try to do full scale, check the range of your VCXO first. The digital >> test is much easier if you already know where your VCXO stops tuning. >> >> Bob >> >> >> >> On Jan 29, 2012, at 1:45 PM, Javier Herrero<[email protected]> wrote: >> >>> I'm now gathering the unit self-updating of DDS data, that will take >>> somewhat long... so I will try later or tomorrow. Since we have seen that >>> the DDS values are reported back in a response to a command, it is easy to >>> do without the need to have anything hooked to the SPI bus :) >>> >>> Regards, >>> >>> Javier >>> >>> El 29/01/2012 19:37, Scott Newell escribió: >>>> At 05:45 AM 1/29/2012, Javier Herrero wrote: >>>> >>>>> For example, the following data has been gathered: >>>>> >>>>> Serial offset 00 00 00 00 >>>>> DDS A word: 44 02 62 F6 = 1141007094 = 5 313 228.32219 Hz >>>>> DDS B word: 43 FD CC 8E = 1140706446 = 5 311 828.32085 Hz >>>> >>>> Can you do a test at +/- fullscale offset as well? >>>> >>>> This is a very exciting discovery. Nice work! >>>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > -- > ------------------------------------------------------------------------ > Javier Herrero > Chief Technology Officer EMAIL: [email protected] > HV Sistemas S.L. PHONE: +34 949 336 806 > Los Charcones, 17 FAX: +34 949 336 792 > 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
