Document how the sensors degrade over time.

2 files changed, 31 insertions, 6 deletions

diff --git a/share/man/man4/mbg.4 b/share/man/man4/mbg.4
index 28fbd3e3a16..ef420787f4a 100644
--- a/share/man/man4/mbg.4
+++ b/share/man/man4/mbg.4
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: mbg.4,v 1.11 2007/11/11 18:19:05 jmc Exp $
+.\"	$OpenBSD: mbg.4,v 1.12 2007/11/26 23:05:28 mbalmer Exp $
 .\"
 .\" Copyright (c) 2006 Marc Balmer <mbalmer@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: November 11 2007 $
+.Dd $Mdocdate: November 26 2007 $
 .Dt MBG 4
 .Os
 .Sh NAME
@@ -50,6 +50,28 @@ Currently, the following cards are supported by
 PCI Express DCF77 time signal station receiver card
 .El
 .Pp
+The quality of the timedelta is reported as the sensor status:
+.Bl -tag -width "CRITICALXX" -offset indent
+.It UNKNOWN
+No valid time information has been received yet.
+.It OK
+The time information is valid and the timedelta is safe to use for
+applications like
+.Xr ntpd 8 .
+.It 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.
+.It 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.
+.El
+
+.Pp
 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:
 .Bl -tag -width "CRITICALXX" -offset indent
diff --git a/share/man/man4/nmea.4 b/share/man/man4/nmea.4
index 25d4b981e20..97fdc4d8042 100644
--- a/share/man/man4/nmea.4
+++ b/share/man/man4/nmea.4
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: nmea.4,v 1.17 2007/11/03 17:26:25 jmc Exp $
+.\"	$OpenBSD: nmea.4,v 1.18 2007/11/26 23:05:28 mbalmer Exp $
 .\"
 .\" Copyright (c) 2006, 2007 Marc Balmer <mbalmer@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: November 3 2007 $
+.Dd $Mdocdate: November 26 2007 $
 .Dt NMEA 4
 .Os
 .Sh NAME
@@ -64,10 +64,13 @@ The time information is valid.
 The timedelta is safe to use for applications like
 .Xr ntpd 8 .
 .It WARN
-The attached GPS receiver indicates a warning condition.
+The attached GPS receiver indicated a warning condition for at least the
+last ten minutes.
 The timedelta should be used with care.
 .It CRITICAL
-tty timestamping has been turned on but there is no PPS signal present.
+tty timestamping has been turned on but there is no PPS signal present or the
+GPS receiver indicated a warning condition for at least the last twenty
+minutes.
 Check your hardware.
 Some GPS units need PPS to be manually turned on.
 .El