[ntp:questions] SIRF time output wobble, GPS or NTP fault?
David J Taylor
david-taylor at blueyonder.co.uk.invalid
Tue Mar 6 19:30:41 UTC 2012
"unruh" <unruh at invalid.ca> wrote in message
news:Obt5r.32277$HR6.15856 at newsfe21.iad...
> Since a 1 second error in nmea would also impact the PPS output, his
> observation is far from irrelevant. That was what happened with the
> Garmin 18x-- the nmea offset became greater than a second, and all hell
> broke out.
So you agree with me, that the NMEA output is not to be trusted. However,
it should not be an issue in a GPS designed and specified for timing
purposes, and working to specification.
But Ron's BU-353 GPS is not designed for timing, and there is no
specification on the datasheet saying when the sentences are output
relative to the second edge. The device has /no/ PPS output. It is
unsuitable for NTP.
More information about the questions