On 8/26/2011 13:14, A C wrote:
On 8/26/2011 02:30, David Lord wrote:
A C wrote:
I will try to capture the outgoing serial data sometime either this
weekend or the next when I have a bit more time. I'll send it along to
the list as soon as I do. For now I'll leave things using PPS only and
see how it works. But I still want to eventually get the GPS refclock
working along with PPS just to have a backup clock for network outages.
Ok, so I've spliced up a serial tap cable to snoop on the data heading
out towards the GPS. Unfortunately I can't seem to decode it. No
amount of changing baud rates, stop bits and parity seems to show me
anything but a stream of unreadable binary data.
It seems to be coming out at 4800 baud although stty says the output
speed of the port is 9600. The data seems to have a regular pattern to
it with a few of the bytes changing.
If anyone can think of a utility that will attempt to autosync to the
data I'm open to suggestions. Otherwise I can try to capture the raw
data if anyone wants to look at it. Either way, it only transmits
while ntpd is using the port. If ntpd is shut down the data stops.
From type 20 driver reference:
Generic NMEA driver sends a $PMOTG,RMC,0000*ID<cr><lf>
command each poll interval?
Except I'm not using the Type 20 NMEA driver. I only have the 22
PPS_ATOM driver enabled.
Let me add that I'm using only the PPS_ATOM right now (GPS_NMEA is not
in the ntp.conf file at all) and the 64-ish bytes of binary data is
showing up at the serial port once per second.
However, even with a debug level of 10 I don't show anything being
written to the port.
_______________________________________________
questions mailing list
[email protected]
http://lists.ntp.org/listinfo/questions
