Re: Keypad update and real time clock.

Howard Hedlund

Hello Mr. Mella

It may be that your Real Time Clock's (RTC) built in battery has died.
Your keypad is now over eight years old. However, to date, we have
had so few RTC problems, that we really aren't sure what to expect when
one does go bad. One question: when entering the time in the setup
menu, does your keypad give you a "beep" when you press GOTO to save the
new time setting? (I hope that you are pressing GOTO and not MENU!)
Also, does the keypad remember the time that you set, even though it no
longer advances, or does the keypad just display random garbage for the
time and date?

I do not believe that the keypad firmware update has anything to do with
the RTC failure, but you are certainly welcome to try re-loading the
firmware. If you do this, I would delete your current v.4.15 loader
from your computer and download a new copy from the internet, just in
case a bit or two was lost in cyberspace on your original download from
the internet. It won't do any good to re-load something that is
already corrupted!

Some of the keypads produced over the years have RTC's that are held in
place by a soldered retaining bar. Others are simply held in place by
a clip on either side. If your keypad has the version with the clips,
it will be relatively easy to change the RTC. If it has the soldered
retaining bar, you may wish to send it in for service (through Unitron,
of course).

I am currently researching the RTC issue with our manufacturer for you
and one other customer. Please contact me directly for more

In the mean time, you can use the mount, but you will want to do the
following, since the keypad can no longer keep time. I am assuming
that the keypad's time will remain as you set it and simply won't
advance. In other words, the time value won't corrupt into nonsense;
it just won't go forward after it is set. If the time and date turn to
garbage, you will need to initialize the mount via a computer - see

1. When you start out, power up the mount just long enough to set
the correct time and date in the setup menu. You may want to set it a
minute or so fast, since it will no longer advance the time, and you
need a minute or so for the next step. You must be in auto-connect =
NO to proceed. If you need to change the auto-connect setting, do that
now also.
2. Power down the mount, wait a few seconds and then power it back
up again. As long as the time hasn't corrupted in the short time since
you set it, the keypad will now send the correct starting time and date
to the GTOCPx control box.
3. Go through your normal start up routine: enter your location #,
and then either polar align or do a star sync. You should probably not
use resume from park or resume from reference park.
4. Once you are at the main menu, press 4=Time/LST
5. The time and date that you entered in step one should be
showing. This step is just to verify that garbage time was NOT sent to
the GTOCPx control box.
6. The GTOCPx control box will now be keeping its own time. It
only needs the initial time and date from the keypad. After that, the
GTOCPx will perform all of its own calculations based on its own
internal oscillator. It will perform goto's as it should, and will
know when to flip sides. The GTOCPx will know the correct LST, even
though the keypad will not. You can verify that time is being kept in
the control box by using the 3=Get Time/Loc FrMnt command in the
keypad's 2=Setup -> 1=Locations and Time -> 2=Set Date and Time menu.
7. Keep in mind as you observe, that the Keypad's LST or "Z" value
will be wrong. This could be confusing since the Keypad displays the Z
value every time you choose a star as your observing target.
8. Do not use a park position at the end of your session. The
keypad sends calculated RA and Dec coordinates to the mount for a park,
and it will not calculate these correctly without the correct time.
You could send the scope into the pier.

Another possibility is to initialize the mount with a computer program
like PulseGuide. You can still use the keypad for all of your GoTo's,
you simply will not use it to establish time and location or to park the
mount. Good luck, and let me know if I can be of further help.


Mag. 7 skies!

Howard Hedlund

Astro-Physics, Inc.



From: ap-gto@... [mailto:ap-gto@...] On Behalf
Of bill_lombardo_bill
Sent: Saturday, April 12, 2008 11:54 AM
To: ap-gto@...
Subject: [ap-gto] Keypad update and real time clock.

Help me to understand.
After upgrading the keypad to firmware 4.15 and after favourably
checking Status "All system go", in a mount 400GTO purchased in October
2000, the Time, Date,GMT,LST and Photo Timer no more update and no more
advance as before (red lights blink but do not change digits in
Could it be Real Time Clock Battery exhausted or could it be for some
other reason I can't understand?
Do you think I can still make use of the mount or I have to change RTC

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