MSTS(4)                   OpenBSD Programmer's Manual                  MSTS(4)

NAME
     msts - Meinberg Standard Time String timedelta sensor

SYNOPSIS
     pseudo-device msts [count]

DESCRIPTION
     This line discipline interfaces serial Meinberg devices.

     The line discipline is enabled by the following sequence:

           #include <sys/ttycom.h>
           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

SENSOR STATES
     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
     itself:

           OK          The clock is synchronized, e.g. a GPS receiver has a
                       fix.

           WARN        The device issued a warning condition, e.g. a GPS re-
                       ceiver has no fix.

SEE ALSO
     tty(4), ldattach(8), ntpd(8), sysctl(8)

HISTORY
     The msts interface first appeared in OpenBSD 4.3.

AUTHORS
     The msts line discipline was written by Marc Balmer
     <mbalmer@openbsd.org>.

OpenBSD 4.7                       May 6, 2008                                1
