Hello,

today, I tried to run my astrophysics 900GTO mount with INDI. Actually it is hard to find out which driver should I use. I have the GTO CP2 with chip version "D". It seems like only the "astropysics" driver works with this chipset (I cant find lx200ap in the drivers list anymore...). But this one has a serious problem. It does no do a meridian flip.

To reproduce this:
1. start the indiserver with der astrophysics driver.
2. prior connection set in the options meue "simulation on"
3. connect to simulation (with skychart in my case)
4. initialize with current dateTtime and location (using cold init).
5. move from "park3" at the pol to any star 45° in SE
Now the "pier side" states correctly: "West, pointing east"
Problem:
6. When I now slew to any star in 45° SW the mount directly slews there and the peir side stays "West,pointig east"

Where is the meridian flip. With my real telescope, I would have now crashed...
What I am doing wrong?

Regards,
Daniel

Hi Daniel,
You can use the Astrophysics or Astrophysics GTOCP2 driver for your mount with the GTOCP2 controller. The Astrophysics Experimental driver is for the GTOCP3 and CP4 controllers with the latest firmware.

The meridian flip feature is handled by the AstroPhysics GTO controller, in your case the GTOCP2. The INDI driver does not handle that logic for these mounts. For this to work properly you would need to be sure to do the following:
1. The GTOCP2 controller has to be initialized with the proper location and time (daylight savings set appropriately, UTC offset, etc.)
2. If you have a good polar alignment then a one star sync is needed or if you have a rough polar alignment then a 2 star sync will do.
3. This initialization is done with the hand control or the INDI driver when using KStars so be sure you have all the proper settings in KStars.
4. Once this is done properly then your mount will do a meridian flip after it receives a goto command and the object has crossed the meridian. For example if you were imaging an object and during the exposure it crossed the meridian and you have the setting in the Ekos image tab set to flip meridian if HA>0 then before the next exposure starts a new goto command is issued to the same object by Ekos and the mount will know to flip as the GTOCP2 handles the logic.

For more detail please see the controller manual as well as this reference for the INDI driver:
www.indilib.org/devices/telescopes/astrophysics.html

I hope this helps clarify why the simulation didn't do the meridian flip since that is handled within the GTOCP2.

So I spent the last few hours overhauling the documentation for Astrophysics driver and separating them into 3 drivers. The updated documentation is here:

www.indilib.org/devices/telescopes/astrophysics.html

I took the liberty of also using @LinuxUser tip above regarding merdian flip in the AP category documentation.

Please let me know your feedback on this.

The legacy driver is the driver that was the default before I started making some big changes and decided to do those in the experimental driver, leaving the indi_lx200ap driver as it was so people could use it if the experimental driver was causing issues.

The indi_lx200ap driver already has functionality that needs a mount later than CP2 so I'm not really clear on how things work right now. I guess the CP2 controller just ignores the protocol requests from the INDI driver that it doesn't understand.

I'm wasn't even aware of the gtocp2 driver so I really don't know how well it works.

I'm focusing on the experimental driver and adding features to it as AP documents more of the newer protocol.

Hopefully if there is interest in a CP2 level driver that someone who owns that hw can work on the driver as I don't currently have plans for that.

Dear all,

sorry for my late reply. It was just not possible for me to come back earlier to do any tests with this mount.

First of all, thank you very much for the tips and the update to the manual.

I now learned, that the mount does the meridian flip by itself. In my case problem was the time, that was not properly set.
On the mount, I used the local time, in INDI too, but in between I used the Ascom-driver in windows. The "update mount-time"-feature leads to an time-offset in the mounts hand-controller. Afterwards, of course the mount believed, that it doesn't has to do the meridian flip.
So, to properly run the astrophysics driver, one has to be sure, that the mounts hand-controller has the same time, like the operating system as well as Kstars.

The mount now works well. Thank you again very much!

Nevertheless, I observed some little bugs regarding the manual as well as with astrophysics legacy driver:

1.) Parking: The park-position can be defined properly. In my case it is "park4" (Alt=0°, Az=180°). The telescope slews directly to those coordinates and finishes the movement. Unfortunately INDI ist waiting for some communication with the mount, even if the mount has stopped (I waited for one minute).

By the way, the manual explains, that custom park-positions are supported. Later it explains that it assumes that the mount parks in the "park3" position. What is true?

2.) Polar alignment with EKOS: the camera takes one image and the solver runs successfully. Afterwards the mount rotates the scope. Unfortunately after this motion is completed the software waits for something that never comes. There is no possibility to tell the script, that the motion is already completed, so it hangs forever.

3.) Motion-control - In EKOS the motion buttons are working fine you click, the mount moves, you click again, the mount stops moving. Unfortunately the "abort-button" is in the "Main-control" section, so it is risky to use this feature.
In other INDI-clients, like "Skychart", or "Indi-starter" this feature does not work. The mount starts moving by the first click, but can only be stopped or reversed after using the "abort-button" in the "main-control-window".

4.) To initialize the scope the date and time has once to be specified. I would like to see a little information on the date-time format the driver accepts. Without trying kstars it was not possible to find this out. For me it is unclear why there is no button with "use system time".

5.) I was missing, the feature to extend the meridian flip (HA>0) using INDI. Since this is a feature connected to the mount, it is not easy to figure out, that this is already implemented and can be found in imaging tab of EKOS. Especially, If I don't use INDI to control my CCD, this feature is not available. I think it might work, using the CCD-Simulator. But what happens, if I don't use Kstars? I was not able to test this feature up to now.

Regards,
Daniel

Daniel, thanks for the detailed report! I'll answer what I know.

2) Need log to check why it remained as is.
3) Please use the Mount Control Panel to control the mount (It's the T icon in the toolbar). It looks like you're using the INDI Control Panel directly.
4) KStars should automatically send these information by default upon establishing connecting with the mount. It is up to the client (KStars, SkyCharts..etc) to communicate this information to the driver.
5) Meridian-flips are not implemented in the driver, they're implemented client-side, so the client has to decide when to initiate the flip. Currently, I believe only KStars supports this, but any other client can implement this feature if they so desire.