Why did my Delorme Earthmate PN-60w SE know the time but not the date?
Mark F
I didn't use it from about 2010 October until 2011 April 7.
After charging the battery I turned on the device indoors.
It was able to "hear" 2 satellites, which is reasonable since I was
indoors.
The device couldn't get a fix, it displayed the correct time
(to human perceptions: seemed like it matched the time on my computer
which I had just set via the network.)
However, even though I gave the device at least 3 minutes while
the Satellite display always showed one particular satellite as
being received (green), the date remained as
October 10, 2010.
October 10 may or may have been the last date that I had the
device turned on where it could get a fix, but I certainly
was in October.
I brought the device outside and in less than a minute the
date displayed correctly. The location displayed correctly
at about the same time, but I don't know if the location was
determined before or after the date was displayed correctly.
Does it really take more than a minute before any given satellite
transmits a day?
In addition, I feel that the device should have displayed an
error code for the date if it didn't really know what the
date was: should I report this as a problem to Delorme, or
I being too picky. (I wouldn't want the a date error indication
if it is normal for the Week not to be correctly
received for 5 or more minutes while the time was received
often enough to get accurate location information, but in the
special case where the device was just turned on I think it
should give an error indication if the date can't be displayed.)
Ed M.
http://support.delorme.com/questions.php?questionid=136
"Last Updated
23rd of February, 2011
Earthmate® GPS PN-60 Firmware Update 3.2
The Earthmate GPS PN-60 Firmware version 3.2 updates the GPS with the
new features and fixes in the list found below. . . .
* Corrected issue where occasionally the PN would not display the
correct time after a reboot"
The DeLorme User Manual ( http://files.delorme.com/manuals/pn60manual.pdf
), pg. 18, defines, "Green–The receiver is tracking the satellite,
ephemeris data is available, and the satellite is being used for
navigation." So your unit should have had current ephemeris for at
least one satellite.
A GPS receiver can infer correct date and time from a single satellite
if it has sufficient signal strength to demodulate data. The time of
week is broadcast every 6 seconds. The week number is broadcast every
30 seconds. So it could take over half a minute to acquire all the
necessary data.
The time and date inferred in this way is Coordinated Universal Time
(UTC), or roughly speaking, Greenwich mean time. The DeLorme User
Manual, pg. 82, implies that if the Time Zone setting is Automatic, a
GPS position solution is needed to display the correct time.
If the firmware update doesn't correct the date display issue, you
could post an item here:
http://forum.delorme.com/viewforum.php?f=160
http://forum.delorme.com/viewforum.php?f=181
or contact DeLorme tech support directly:
Mark F
wrote:
> May be related to this firmware update:
>
> http://support.delorme.com/questions.php?questionid=136
>
> "Last Updated
> 23rd of February, 2011
>
> Earthmate® GPS PN-60 Firmware Update 3.2
> The Earthmate GPS PN-60 Firmware version 3.2 updates the GPS with the
> new features and fixes in the list found below. . . .
> * Corrected issue where occasionally the PN would not display the
> correct time after a reboot"
Might be related but I can't tell yet. I will call Delorme next week
to see if it is. When I called last week they didn't ask me what
version I had and didn't suggest that I do an update.
I have Version: 3.0.497860, so it is definitely out of date.
>
> The DeLorme User Manual ( http://files.delorme.com/manuals/pn60manual.pdf
Thanks for the link to the machine readable version of the
documentation. I couldn't convince the search function at the Delorme
site to tell me the location.
Mark F
On Sat, 09 Apr 2011 21:05:11 -0400, Mark F <mark...@gmail.com>
wrote:
I'm sure that I waited more than 1 minute and the signal was weak
from time to time and the week number was missed even though the time
was received. (When I called DeLorme about the problem I asked if it
could be the case that the Week information wasn't sent as often
the time information, but the tech support guy didn't seem to know the
answer. I now am back to what I thought before I called DeLorme, which
is that the Week information was missed a couple of times, which would
be a normal occurrence and suggest that the display be flagged to
indicate "time known but date not known".)
Thanks again
Mark F
wrote:
> (Sorry, I left out some comments.)
> On Sat, 09 Apr 2011 21:05:11 -0400, Mark F <mark...@gmail.com>
> wrote:
>
> > On Fri, 8 Apr 2011 12:39:17 -0700 (PDT), "Ed M." <pat_...@yahoo.com>
> > wrote:
> >
> > > May be related to this firmware update:
> > >
> > > http://support.delorme.com/questions.php?questionid=136
> > >
> > > "Last Updated
> > > 23rd of February, 2011
> > >
> > > Earthmate® GPS PN-60 Firmware Update 3.2
> > > The Earthmate GPS PN-60 Firmware version 3.2 updates the GPS with the
> > > new features and fixes in the list found below. . . .
> > > * Corrected issue where occasionally the PN would not display the
> > > correct time after a reboot"
> > Might be related but I can't tell yet. I will call Delorme next week
> > to see if it is. When I called last week they didn't ask me what
> > version I had and didn't suggest that I do an update.
> >
> > I have Version: 3.0.497860, so it is definitely out of date.
I updated to the software from:
"Earthmate GPS PN-60 Firmware Update 3.2"
from:
http://support.delorme.com/questions.php?questionid=136
The Earthmate PN-60w SE page: Settings > About this Device...
now indicates:
Build: Feb 1 2011, 09:20:17, Version: 3.2.590196 / na
I have confirmed that an incorrect date can be still be displayed with
a correct time and have suggested to Delorme that the display be
changed to indicate when the date (i.e., WEEK) is not known to be
correct.)
Thanks to everyone who posted and replied directly. I know that on
the whole it is a trivial issue, but when I see a date that I know
to be wrong I lose confidence in the device.