xref: /openbsd/share/man/man4/umbg.4 (revision 771fbea0)
1.\"	$OpenBSD: umbg.4,v 1.6 2019/03/26 16:41:35 jmc Exp $
2.\"
3.\" Copyright (c) 2007 Marc Balmer <mbalmer@openbsd.org>
4.\"
5.\" Permission to use, copy, modify, and distribute this software for any
6.\" purpose with or without fee is hereby granted, provided that the above
7.\" copyright notice and this permission notice appear in all copies.
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9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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17.Dd $Mdocdate: March 26 2019 $
18.Dt UMBG 4
19.Os
20.Sh NAME
21.Nm umbg
22.Nd Meinberg Funkuhren USB5131 and DCF600USB timedelta sensors
23.Sh SYNOPSIS
24.Cd "umbg* at uhub?"
25.Sh DESCRIPTION
26The
27.Nm
28driver provides support for Meinberg Funkuhren USB5131 and
29DCF600USB time signal receivers for the German DCF77 station.
30.Nm
31implements a timedelta sensor and the delta (in nanoseconds) between the
32received time information and the local time can be accessed through the
33.Xr sysctl 8
34interface.
35.Pp
36The quality of the timedelta is reported as the sensor status:
37.Bl -tag -width "CRITICALXX" -offset indent
38.It UNKNOWN
39No valid time information has been received yet.
40.It OK
41The time information is valid and the timedelta is safe to use for
42applications like
43.Xr ntpd 8 .
44.It WARN
45The time information is still valid, but no new time information has been
46decoded for at least twelve hours due to a reception or parity error.
47The timedelta should be used with care.
48.It CRITICAL
49No valid time information has been received for more than twelve hours since
50the sensor state degraded from OK to WARN.
51This is an indication that hardware should be checked
52to see if it is still functional.
53.El
54.Pp
55A second sensor provides the relative signal quality as a percentage.
56The status of this sensor is used to report the status of the device itself:
57.Bl -tag -width "CRITICALXX" -offset indent
58.It OK
59The clock is synchronized.
60.It WARN
61The device's clock is free running on the local oscillator.
62This is not an error and can happen due to the nature of the signal
63transmission using longwave radio.
64.It CRITICAL
65Hardware failure, e.g. communication with the device failed.
66.El
67.Sh SEE ALSO
68.Xr intro 4 ,
69.Xr usb 4 ,
70.Xr ntpd 8 ,
71.Xr sysctl 8
72.Sh HISTORY
73The
74.Nm
75driver first appeared in
76.Ox 4.3 .
77.Sh AUTHORS
78The
79.Nm
80driver was written by
81.An Marc Balmer Aq Mt mbalmer@openbsd.org .
82