[APBeta] APv2b34 scope control problem

Bruce Pipes bruce.pipes at fandm.edu
Fri Apr 17 10:12:37 PDT 2009


Paul,

It would probably be best to put "Park and Disconnect" instead of  
"Slew to Home" to avoid confusion. As Dick points out, the Home  
position is used for initial alignment, whereas the Park position is  
where you leave an aligned scope between sessions.

Bruce
On Apr 17, 2009, at 1:00 PM, Paul Rodman wrote:

> Doh! In AP V1.6 I issue the :hP# command and disconnect. Obviously  
> things got screwed up in translation (AP V2 telescope code is a  
> complete rewrite).
>
> I will correct the problem.
>
> Dick, once again you save the day!
>
> Thanks
>
> Paul R.
>
> On Apr 17, 2009, at 09:37 AM, richard seymour wrote:
>
>> :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.
>
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