Celestron Advanced GT/Nexstar RS-232?
khobar
Starry Night Pro. However, I can't seem to enable RS-232 on the hand
controller.
I also have a Celestron CG-5 Advanced GT mount - same problem, no RS-232
option.
I've tried to find the answer on the net but all I've come up with is that
if the hand controller is using firmware <4.0 then I won't be able to
upgrade them. That's fine, I can live with that for the moment, but I'm
really curious why I can't enable RS-232 communications - everything I've
read says it should be there.
So, I'm hoping someone here might have the answer. Thanks in advance.
John Banister
Are you plugging the cable into the hand controller?
-John
"khobar" <pnix...@cox.net> wrote in message
news:K4Ekh.148411$xM4....@newsfe07.phx...
khobar
news:WMGkh.53266$qO4....@newssvr13.news.prodigy.net...
>
> Are you plugging the cable into the hand controller?
Yes, at the bottom. I have tried on a laptop and a desktop, verified comm
parameters, etc. on the computers and am trying to communicate with Starry
Night Pro and Nexstar Observer List. I also checked continuity on the cable
to make sure it wasn't duff.
Neither hand controller shows RS-232 anywhere on their screens though the
respective manuals do.
RMOLLISE
There isn't an option. The more recent Nexstar HCs don't require you to
turn on the serial interface, just plug in your cable and go. Only the
very early HCs on the first Nexstar scopes needed to be enabled.
If you can't communicate with the HC, your problem is likely:
Bad cable.
Improper port settings in the software.
Hardware problems on the PC end (I occasionally see a serial-usb cable
that just doesn't want to cooperate).
;-)
Peace,
Rod Mollise
Author of:
Choosing and Using a Schmidt Cassegrain Telescope
and
The Urban Astronomer's Guide
<http://skywatch.brainiac.com/astroland>
khobar
news:1167341247.7...@73g2000cwn.googlegroups.com...
> Hi:
>
> There isn't an option. The more recent Nexstar HCs don't require you to
> turn on the serial interface, just plug in your cable and go. Only the
> very early HCs on the first Nexstar scopes needed to be enabled.
>
> If you can't communicate with the HC, your problem is likely:
>
> Bad cable.
> Improper port settings in the software.
> Hardware problems on the PC end (I occasionally see a serial-usb cable
> that just doesn't want to cooperate).
Thanks Rod,
The instructions for the Nexstar GT shows RS-232 in the menu tree, but no
such menu item exists (that I can access). The Advanced GT mount talks about
RS-232 but does not show the RS-232 option in the menu tree mostly because
the instructions are for v. 4.x firmware. Mine is v3.04.
I'm using 9600, 1 stop, 8 data, no parity, no flow control. The cable seems
to be okay - the wires are in the right positions, and the continuity is
good. I don't know if the serial port on the two computers I've tried are
actually working, but I don't see why they wouldn't be (famous last words).
Robert Sheaffer
There is some issue involving datacomm problems on some models of the
Hand Controller. A an old web page by software developer Andre Pacquette
(not up any longer) stated,
"Serial problem with HC:
Not all PC serial ports are made equal. When not in use, most serial
ports idle with a stop bit. However, some serial ports send a
continuous start bit (break signal) when not in use. If the HC serial
port receives a continuous start bit, it gets confused or bogged down
and has difficulties sending characters the next time you connect. For
instance, if you try connecting to the HC with "TheSky" you'll get
errors 9/10 times.
Often, BIOS upgrades are available that will change the serial port
behaviour and work around the problem. Also, you could get a
serial-to-USB device and hope that it idles with stop bits.
Either way, this is a bug with the serial handling on the HC and
hopefully Celestron will correct it on the next spin. "
I played around trying to solve this problem with RTGUI, and found that
programmed delays between the characters seemed to work around the
problem. Try it: http://www.rtgui.com . There's a good chance it may
work.
Robert
khobar
I think the problem is with the hand controller(s) - neither of them can be
set to RS-232 mode with or without a cable connected. I'm sure the Nexstar
80GT is supposed to have a selection for this, but I am less sure about the
Advanced GT mount.
I did as you suggested - I downloaded the RTGUI program. I haven't read a
lot on it yet but initial tests are the same - no indication of
communication.
I found the drivers for my USB-to-serial cable and have tried that. Shows as
COM4 and I set the software appropriately. No luck.
This could all be operator error on my part - I've not connected a mount to
a computer before, so maybe I'm missing an important step?
Anyway, thanks for the input. I'll post back if anything changes.
William Hamblen
<Iam"Roberto"@debunker.com> wrote:
>Not all PC serial ports are made equal. When not in use, most serial
>ports idle with a stop bit. However, some serial ports send a
>continuous start bit (break signal) when not in use. If the HC serial
>port receives a continuous start bit, it gets confused or bogged down
>and has difficulties sending characters the next time you connect.
The standard for serial ports is to mark time while idle, otherwise
you don't know a start bit has arrived. Sending a break all the time
is bad behavior. A break is supposed to be sent only to get the
attention of the other end of the line.
Bud
--
The night is just the shadow of the Earth.
Roger Hamlett
"Robert Sheaffer" <Iam"Roberto"@debunker.com> wrote in message
news:bHKlh.72333$B42....@newsfe12.phx...
>
> There is some issue involving datacomm problems on some models of the
> Hand Controller. A an old web page by software developer Andre Pacquette
> (not up any longer) stated,
>
> "Serial problem with HC:
>
> Not all PC serial ports are made equal. When not in use, most serial
> ports idle with a stop bit. However, some serial ports send a
> continuous start bit (break signal) when not in use. If the HC serial
> port receives a continuous start bit, it gets confused or bogged down
> and has difficulties sending characters the next time you connect. For
> instance, if you try connecting to the HC with "TheSky" you'll get
> errors 9/10 times.
> Often, BIOS upgrades are available that will change the serial port
> behaviour and work around the problem. Also, you could get a
> serial-to-USB device and hope that it idles with stop bits.
> Either way, this is a bug with the serial handling on the HC and
> hopefully Celestron will correct it on the next spin. "
>
> I played around trying to solve this problem with RTGUI, and found that
> programmed delays between the characters seemed to work around the
> problem. Try it: http://www.rtgui.com . There's a good chance it may
> work.
Sending a 'break' for a gap in transmission,was commonly done by just one
make of PC. Dell. A little while ago, some of their laptops started doing
this as a way of saving power. It caused problems , not just with the
Celestron HC, but with a huge number of serial communications programs.
There were complaints, and a BIOS fix was launched. Oddly, Dell elected to
make the fix 'standard' on European machines, and not on the US
machines...
This is not a Celestron problem, but a major fault in the PC's concerned.
I have two HC's, neither offer an 'enable' for the RS232. It is enabled
all the time, if the right cable is plugged in.
Best Wishes
khobar
news:505mh.50093$n36....@newsfe7-gui.ntli.net...
> 'Break', implies what it says. The link is broken.
> Sending a 'break' for a gap in transmission,was commonly done by just one
> make of PC. Dell. A little while ago, some of their laptops started doing
> this as a way of saving power. It caused problems , not just with the
> Celestron HC, but with a huge number of serial communications programs.
> There were complaints, and a BIOS fix was launched. Oddly, Dell elected to
> make the fix 'standard' on European machines, and not on the US
> machines...
> This is not a Celestron problem, but a major fault in the PC's concerned.
> I have two HC's, neither offer an 'enable' for the RS232. It is enabled
> all the time, if the right cable is plugged in.
>
> Best Wishes
Roger,
Many thanks for the input. What you've said would certainly explain why I
dont' see the RS-232 option, but it begs the question as to why Celestron
would show the option in their manual (for the Nexstar 80GT) and why
software would state that if communications fail the HC needs to be put into
RS-232 mode.
I'm certainly not trying to argue - I'm the one who has zero experience with
these HC's, but it seems these HC's are not all created equal (or there's
somethine else going on).
What I've tried thus far:
PC's in question: an IBM Thinkpad laptop (T23) and a "home built"
NForce4-based A64 desktop, using the serial cable.
I have also installed the driver for the USB-2-serial cable and have tried
communicating from the desktop. No go. COM settings of 9600,8,1,none.
All the best,
Robert Sheaffer
"Menu->RS-232", and it doesn't care whether or not a cable is connected.
If it doesn't have that setting, then the RS-232 is always enabled.
Are you trying to use the same hand controller on both mounts? I don't
think that works. All of the small Nexstars can use the same hand
controllers (60/80/114), you need to "select model." But not the other
series....
Robert
khobar
>I have a Celestron Nexstar 114 mount. The RS-232 is enabled by
> "Menu->RS-232", and it doesn't care whether or not a cable is connected.
>
> If it doesn't have that setting, then the RS-232 is always enabled.
>
> Are you trying to use the same hand controller on both mounts? I don't
> think that works. All of the small Nexstars can use the same hand
> controllers (60/80/114), you need to "select model." But not the other
> series....
Hi Robert,
You (and RMOLLISE) both suggested RS232 was enabled all the time if it
didn't show up as an option. Since the chances of two different HC's being
bad, or two different computers having duff serial ports was low, I decided
to check the cable again.
It's really amazing how one can look at a picture and check with an ohmeter
and determine nothing is wrong if one neglects to actually look at the pin
numbers. It turned out that my DB9 was miswired. Fortunately I was able to
salvage a replacement from the pile of cables in my garage. I rebuilt the
RS232 cable with the correct pinouts and now BOTH telescopes are able to
communicate with Nexstar Observer List (at least - this is the only sw I
tried so far). Good results, thank you.
I very much appreciate the help from everyone and wanted to let everyone
know how things turned out.
Thanks again.