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
HISTORY
The umbg driver first appeared in
OpenBSD 4.3.
AUTHORS
The umbg driver was written by
Marc Balmer
<mbalmer@openbsd.org>.