MSTS(4) BSD Kernel Interfaces Manual MSTS(4)
msts -- Meinberg Standard Time String timedelta sensor
pseudo-device msts [count]
This line discipline interfaces serial Meinberg devices.
The line discipline is enabled by the following sequence:
int ldisc = MSTSDISC, fildes; ...
ioctl(fildes, TIOCSETD, &ldisc);
The byte stream is unaltered by the line discipline which maintains a
timedelta sensor using the MSTS data. The timedelta sensor will appear
as msts* in the list of sensors and the delta (in nanoseconds) between
the received time information and the local time can be accessed through
the sysctl(8) interface.
The Meinberg radio clocks use the following default baudrates:
GPS-receivers (external and PCI, COM0) 19200/8N1
GPS-receivers (external, COM1) 9600/8N1
DCF77-receivers (external) 9600/7E2
DCF77-receivers (PCI) 4800/8N1
The quality of the timedelta is reported as the sensor status:
OK The time information is valid. The timedelta is safe
to use for applications like ntpd(8).
WARN The attached receiver has been indicating a warning
condition for at least the last ten minutes. The
timedelta should be used with care.
CRITICAL tty timestamping has been turned on but there is no PPS
signal present or the receiver indicated a warning con-
dition for at least the last twenty minutes. Check
your hardware. Some receiver units need PPS to be man-
ually turned on.
The status of a second sensor is used to report the status of the device
OK The clock is synchronized, e.g. a GPS receiver has a
WARN The device issued a warning condition, e.g. a GPS
receiver has no fix.
tty(4), ldattach(8), ntpd(8), sysctl(8)
The msts interface first appeared in OpenBSD 4.3.
The msts line discipline was written by Marc Balmer
BSD January 15, 2015 BSD