Hi Peter,

> I entered them in the ASCOM driver. Finally I rechecked that driver and they were there.

If you are using APCC with the ASCOM driver, then APCC will initialize the mount. So, the place you should set up the lat/long coordinates is in the Sites dialog in APCC. Here's a screenshot:

-Ray

Hi Bill,

>> Home would work even with the mount lost.

does this also apply to a mount without absolute encoders?

Kind Regards,

Horia

Bill is correct. Not only that, both Latitude and Longitude are incorrectly set to 0 at one point:

0000050 2021-08-01 00:40:54.250:      Debug,  Command Thread, TX = ':Gt#'

0000051 2021-08-01 00:40:54.250:      Debug,        UDP Send, --> :Gt#   Timeout(msecs)= 100

0000052 2021-08-01 00:40:54.252:      Debug,        UDPReply, <-- +00*00:00#      (1 msecs)

0000053 2021-08-01 00:40:54.252:      Debug,  Command Thread, TX=':Gt#'|RX='+00*00:00#'

0000054 2021-08-01 00:40:54.253:      Debug,  Command Thread, TX = ':Gg#'

0000055 2021-08-01 00:40:54.253:      Debug,        UDP Send, --> :Gg#   Timeout(msecs)= 100

0000056 2021-08-01 00:40:54.255:      Debug,        UDPReply, <-- +00*00:00#      (2 msecs)

0000057 2021-08-01 00:40:54.255:      Debug,  Command Thread, TX=':Gg#'|RX='+00*00:00#'

Power off the mount if it is not off already. Then power on the mount and run APCC . Watch APCC to make sure that it initializes the mount with the proper Lat/Long values. If something else initializes the mount first (e.g. the keypad?) you will not see APCC’s popup initialization window, and APCC will not set the mount’s latitude and longitude. You can check thevalues set in the mount on APCC’s Site tab.

-Ray

@Wade:

> I hope that this makes sense,

Very helpful.  Thank you.

Linwood

My suggestion is to regard “find home” as a recovery tool.

In about 10 years of using Astro-Physics mounts, I’ve never actually used the “find home” feature.  In my normal workflow, I have my automation set to park the mount in Park 4 at the end of a session.  If I am going to remove the OTA, I manually park it at Park 3.  And as Roland says, there’s no need to park the mount at all.  Just power it down when you are done.  I have my mounts configured to unpark from “last parked”, so when I want to star a session, I just turn them on and go.

I have had a handful of cases in that time where I managed to get a mount lost.  It was never in a normal workflow.  Most of the time, it was when I was experimenting with some unreleased mount control software.  Since I’m not a remote imager, I just recovered the mount manually, although “find home” would have worked as well.

I also never loosen the clutches, unless I’m recovering from a lost situation.

Regarding sync versus recalibrate, recalibrate is your friend.  Recalibrate works like a sync on most other mounts.  Essentially, it says “forget where you think you are pointed, you are pointed here.”  Sync is similar, but adds one more nuance.  Specifically, sync is just like a recal, but in addition to saying “you are here”, it also says “and the counterweights are down”.  It’s not immediately obvious why you would want to tell the mount whether the counterweights are up or down.  The reason is that, for any position in the sky, there are two ways that the mount can point there.  One way is what we usually see, with the telescope above the mount and counterweights below.  But you can also point at any position in the sky with the counterweights above the mount and the telescope below.  An Astro-Physics mount is very flexible, and will point with the counterweights up if you want it to.  The purpose of a sync, as opposed to a recal, is so to tell the mount that the counterweights are down.  The gotcha here is that if you are pointed near the meridian, the counterweight shaft is nearly parallel to the ground.  If you are not careful, and do a sync near the meridian, you might accidentally do the sync with the counterweights imperceptibly up.  When that happens, the mount will always slew with the counterweights up and scope down.

My suggestion is to avoid doing a sync, ever. The exception is if you are recovering from being lost.   I can’t remember the last time I did a sync.  The ASCOM driver has a feature to convert “sync” commands to “recal”.  The feature is enabled by default, and you should probably never disable it.

I hope that this makes sense,

-Wade

Thanks.

@Roland said:

I believe that the “known parking positions” are all based on how the mount thinks it’s oriented with respect to the sky.  I believe that the “find home” will position the mount relative to a known axis position, independent of the sky.  With an encoder mount like your AE, “find home” will use the encoders and will be very, very accurate.  It will also recalibrate the mount so that it knows where it’s pointed with respect to the sky.

The implications here are that if you do an errant recalibrate or sync, the known park positions will no longer be correct.  The find home feature is intended to recover from that.

Regarding the clutches, if you have an AP1100AE or AP1600AE, then releasing the clutches and moving the mount will be something that the encoders don’t “see”, so you will need to re-establish the home position if you do that.  With a Mach2, I believe that the encoders are always correct, even if you release the clutches and move the mount, so there is never a need to re-establish the home position.

I hope that makes sense,

-Wade

@Roland said: