UMBG(4) FreeBSD Kernel Interfaces Manual UMBG(4)
NAME
umbg - Meinberg Funkuhren USB5131 and DCF600USB timedelta sensors
SYNOPSIS
umbg* at uhub?
DESCRIPTION
The umbg driver provides support for Meinberg Funkuhren USB5131 and
DCF600USB time signal receivers 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 <
[email protected]>.
FreeBSD 14.1-RELEASE-p8 March 26, 2019 FreeBSD 14.1-RELEASE-p8