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

NAME
     mbg - Meinberg Funkuhren timedelta sensor

SYNOPSIS
     mbg* at pci?

DESCRIPTION
     The mbg driver provides support for Meinberg Funkuhren radio clocks (time
     signal station and GPS receivers).  mbg implements a timedelta sensor and
     the delta (in nanoseconds) between the received time information and the
     local time can be accessed through the sysctl(8) interface.

     The card type is indicated in the sensor description.  Currently, the
     following cards are supported by mbg:

           GPS170PCI  3.3V/5V 6-channel GPS receiver card
           PCI32      5V DCF77 time signal station receiver card
           PCI509     5V DCF77 time signal station receiver card
           PCI511     3.3V/5V DCF77 time signal station receiver card
           PEX511     PCI Express DCF77 time signal station receiver card

     The quality of the timedelta is reported as the sensor status:

           UNKNOWN     No valid time information has been received yet.

           OK          The time information is valid and the timedelta is safe
                       to use for applications like ntpd(8).

           WARN        The time information is still valid, but no new time
                       information has been decoded for twelve hours (four
                       days in the case of a GPS170PCI card) due to a recep-
                       tion or parity error.  The timedelta should be used
                       with care.

           CRITICAL    No valid time information has been received for more
                       than twelve hours (or four days in the case of a
                       GPS170PCI card) since the sensor state degraded from OK
                       to WARN.  This is an indication that hardware should be
                       checked to see if it is still functional.

     A second sensor provides the relative signal quality as a percentage.
     The status of this sensor is used to report the status of the device it-
     self:

           OK          The clock is synchronized.

           WARN        The device's clock is free running on the local oscil-
                       lator.  For DCF77 receiver cards this is not an error
                       and can happen due to the nature of the signal trans-
                       mission using longwave radio.

           CRITICAL    Hardware failure, e.g. communication with the device
                       failed.

SEE ALSO
     intro(4), pci(4), ntpd(8), sysctl(8)

HISTORY
     The mbg driver first appeared in OpenBSD 4.1.

AUTHORS
     The mbg driver was written by Marc Balmer <mbalmer@openbsd.org>.

OpenBSD 4.7                    November 27, 2007                             1
