#PPS_ATOM refclock flag2 DCD clear, flag3 kernel PPS
#opens /dev/pps1
server 127.127.22.1
fudge 127.127.22.1 flag2 1 flag3 1 refid PPS
This segment gets added if I try to use the GPS data as a clock:
#GPS_NMEA refclock mode 1 $GPRMC only
#opens /dev/gps1
server 127.127.20.1 minpoll 4 mode 1 noselect
fudge 127.127.20.1 time2 0.245 refid GPS
What happens if you reverse the order of these two?
I see there is code that will reset the PPS state upon open, but it should
only happen on the FIRST open of a device; subsequent simultaneous opens
should still work. You could always put an extra printf() in that code
in zsopen() to make sure it's only resetting the PPS capture state once.
You could also easily test outside of ntpd with the existing tools to
see if a second open a device stops PPS capture.