[APBeta] APv2b34 scope control problem

[richard seymour]

:hF# ???

That's not a "slew to home" (similar to Park),
it's an "Align on Home", which is very very very different.
(i'm working from the Protocol description as i write this,
i don't have the time this morning to walk the firmware or
do one on my own)

If it's (as the protocol manual says) an "Align on Home", it will slew to
the "home" position (roughly Az=20), then do a number of level-sensing
tips and tilts at 90 degree intervals, and finally end up (if memory serves)
near Az=200 [two hundred], and theoretically "aligned" **assuming** that
the user did a "Setup/Telescope/Calibrate Home" somewhen in the distant
past, physically mounted as they are now. (the :hC# command).
It was a "feature" to allow you to remotely (re)align the scope "if power
was lost during the session" (so said Meade in a private eMail).
I tried it once in Polar, and it was "fascinating" to watch the gyrations.
Not for the faint at heart.
You can reach it on the keypad by trying an  Setup/Align/Align on Home[enter]

But it is NOT simply a "slew to 'home'" command.

(where's "home", anyway? ... ahh.. you listed the default Polar Park position).
Note: if you use :hP#, the scope will expect to be turned off at the end
of it, and will also stop responding to "where are you?" inquiries.

Note that a user can specify a custom PARK position, which becomes where
the scope expects to be on the -next- power-up, whether you PARKed or not.

If i wanted to slew my scope to DEC=0, Az=180 (base relative), *and*
stop the motors, i'd issue an Alt/Az (:MA#) after sending Terrestrial
coordinates of Az=180, Alt=(90-latitude)

have fun
--dick


Paul Rodman wrote:
> 
> On Apr 17, 2009, at 07:57 AM, Bruce Pipes wrote:
> 
>> I used APv2b34 in a imaging session last night and it passed every 
>> test but the final exam. At the end of the session I clicked "Slew to 
>> Home" on the Telescope Control Palette expecting the scope to slew to 
>> Dec = 0° with the scope pointing south. Instead it slewed to Dec = 
>> +20° and it kept slewing in RA until I had to hit the power off switch 
>> on the scope.
>>
>> I have filed a bug report.
>>
>> Thanks,
>> Bruce Pipes
>> LX200ACF and MacOS 10.5.6
> 
> Looking at the code, what happens is that a :hF# command is issued by 
> the app. According to the Meade documentation (which is often 
> reality-challenged), this should do the job. However, I note that the 
> button has "(and disconnect)" underneath it. This I do not currently do 
> (and probably should). This means that the app will continue to send 
> requests for RA/Dec to the scope. I'm not sure if this would cause the 
> problem (i.e. "Oh, the user want's me to slew to home. OK, here we go. 
> Oh, wait, now he wants the current RA. I'll just conveniently forget 
> about waiting for the home position to be reached, etc. and process the 
> new command instead).
> 
> I've cc-ed this to Dick Seymour, the font of wisdom on these matters. If 
> any body in this universe can shed light on the matter, it's Dick.
> 
> Paul R.
> 
>