Re: APPM Questions


Ray Gralak
 

Hi Shane,

How does APPM send the telescope's destination coordinates to the Dome
driver? Does it do that though ASCOM?
Yes, through ASCOM, but as I alluded to, the API is lacking. It does not provide the dome with enough information to calculate position.

In Active mode, APPM first checks if the driver can accept SendToAzimuth and/or SendToAltitude. Assuming it can APPM will convert the telescope's destination RA/Dec to Azimuth/Altitude and issue the dome driver's SlewToAzimuth() and SlewToAltitude() methods.

In Passive mode, APPM does not issue any moves directly to the dome driver. However, APPM monitors the "Slewing" property to determine when the dome has completed movement. APPM also does this in it's Active mode as well.

The problem with the ASCOM Dome interface is that it doesn't provide enough information to the dome driver. What the dome driver needs are:

1) The telescope's destination RA/Dec.
2) The mount's destination pier side.
3) In case of a multiple scope setup, which telescope (or telescopes) to center the dome opening.

-Ray Gralak
Author of PEMPro
Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver


-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Shane Ramotowski
Sent: Tuesday, October 6, 2020 5:37 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] APPM Questions

Hi Ray,

I'm currently working on motorizing my dome and am in the middle of
testing my newly written ASCOM driver and want to make sure that I can
support APPM.

How does APPM send the telescope's destination coordinates to the Dome
driver? Does it do that though ASCOM?

This is my first ASCOM driver, so I'm likely missing something or
misunderstanding something, but I don't see any ASCOM methods that would
work for sending telescope coordinates. Is it done though a custom
command in Action(), CommandBlind(), CommandBool(), or CommandString()?
I know about the CanSlave property, but as I understand it, that is for
a hardware (external to DOME driver) solution.

Thanks - Shane

On 10/5/2020 8:56 PM, Ray Gralak wrote:
Tony,

APPM sends the telescope's destination coordinates to the Dome driver that to which APPM is configured. IMO
the Dome driver should be intelligent enough to figure out where the telescope is heading and move the dome
there. I would say it is up to the Dome driver developer to make this work. I would say you should talk to the
NexDome manufacturer to see what suggestions they have.

Also, I have been on and off working on a generic cross-platform dome driver. At the rate it's been going, it may
be months away from when I can complete it, but the intent is to fix some of the bad decisions (in hindsight) made
by ASCOM in the API design. (Then I would have to convince application developers to implement what is
essentially a superset of ASCOM.)

-Ray Gralak
Author of PEMPro
Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Tony Benjamin
Sent: Monday, October 5, 2020 7:42 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] APPM Questions

Ray,

Is my understanding on this whole process more or less correct?:



* as soon as I hit "Start" for the APPM run that first RA/Dec (Zenith) is sent to SGP (assuming I'm using SGP
for dome movement);
* SGP does the math required to figure out what Azimuth to send the dome to (should take like a Nano
second - it is a computer after all); and
* that Azimuth position is then sent to the Nexdome driver which then actually has the dome move?

Is that the way things should work? If so, then I would be guessing that the Nexdome driver may be the real
issue
in all this?





--
Shane Ramotowski
kor@cotse.net
https://www.kor-astro.net



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