>Can someone tell me definitively the electrical meaning of pps driver >flag2? More precisely, how should flag2 be set for: > >1. Signal on DCD line normally high, going low at the on-time mark > >2. Signal on DCD line normally low, going high at the on-time mark
RS-232 is upside down, so "assert" means low. So the normal case triggers on a falling edge and the "flag2 1" case triggers on the rising edge. >In each case, it's the initial transition that's on-time; the trailing >edge of the pulse is not precise. Years ago, my Z3801A was off a few 10s of uSec relative to a NMEA receiver. The pulse is 20 uSec wide. Things got happier after I added the "flag2 1" to my config file. It's possible my mods to the Z3801A are different from what others are using. I'm pretty sure I copied Jeff Mock's drections, but of course I made a few "improvements". I think they were all physical rather than logical. On a scope, my pulse is normally low, going high for 20 uSec. (I'm actually standing on my head because the easy place to get a scope probe is before a RS-232 driver. So I could easily have something inverted.) Looks like my comment in http://ntp.isc.org/bin/view/Support/ConfiguringHPZ3801ARefclocks is backwards/confusing. Sigh. -- The suespammers.org mail server is located in California. So are all my other mailboxes. Please do not send unsolicited bulk e-mail or unsolicited commercial e-mail to my suespammers.org address or any of my other addresses. These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
