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
PZF180PEX
    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 reception 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 itself:

OK  The clock is synchronized.

WARN
    The device's clock is free running on the local oscillator. For DCF77 receiver cards this is not an error and can happen due to the nature of the signal transmission 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>.