After reading the manpages for ntpd(8), ntpd.conf(5), & nmeaattach(8), I thought I had enough information to use a USB GPS device as a time source.
In /etc/ntpd.conf, the only line left enabled is: sensor cuaU0 In /etc/rc.conf.local, the only lines are: nmeaattach cuaU0 ntpd_flags="" Yet upon reboot, I see the following message displayed during initialization: nmeaattach: open: /dev/cuaU0: Device busy I can observe the NMEA sentence traffic through cu(1), so it is unclear what I have missed. Any insight would be appreciated. Thanks. Jim