UMBG(4)

NAME
umbg - Meinberg Funkuhren USB5131 timedelta sensor

SYNOPSIS
umbg* at uhub?

DESCRIPTION
The umbg driver provides support for the Meinberg Funkuhren USB5131, a time signal station receiver for the German DCF77 station. umbg 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 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 at least twelve hours 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 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. 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), usb(4), ntpd(8), sysctl(8)

HISTORY
The umbg driver first appeared in OpenBSD 4.3.

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