gnu not unix wrote: > In message <[EMAIL PROTECTED]> you write: > >> Udo van den Heuvel wrote: >> >>> If the commandline at http://time.qnan.org/ for shmpps really configures >>> for low-to-high (i.e.: rising edge) then why do I see -180+ ms offset >>> for my Garmin GPS 18 with rising edge configured? >>> > (...) > >>> So what is the correct way to tell ntpd what's going on? >>> Is there some peculiarity going on? >>> Or am I missing something obvious? >>> > > > You are using a TTL (well, CMOS) level signal to drive the > RS-232 input of your serial port. The expected level conversion > that should be done is thus missing. This level conversion also > does a signal inversion. > > > With a GPS18LVC the unbuffered cmos output should work fine on most serial ports (it does on three machines I've tried it on). So at least with the 18LVC there is no expected inversion and if you do level convert you'll need an extra inverter to make the data side work. I you use it unbuffered then no inversion is needed (i.e. no flag 2) - if there is an inverter in the system (a for example MAX 232 or equivalent) you'll need flag 2.
John _______________________________________________ timekeepers mailing list [email protected] https://fortytwo.ch/mailman/cgi-bin/listinfo/timekeepers
