AOX star fade

Reverting back to the Maxim 6.08 alleviated most of the problems excepting for star fade. Under automation through CCDAP Maxim locates the star and stars to guide. My delay is 10 seconds in CCDAP. Up until that time AOX guides and adjusts to 0.1RMS wander in each axis. Then once the main camera is activated star fade commences.

Anyone got any thoughts? Do I need to provide a log?

 

A further update. The guide star fade problem happens only after the scope has gone off to do something like a meridian flip or focusing run. The AOX reports guide star fade and yet if you stop the AOX software and restart it immediately finds the star.

 

Hi Doug, it does that, then it requires the star and then just after the 10 second delay I have set in CCDAP the AOX software reports star fade and stops guiding on the star. If I get to it fast enough and stop the AOX software and then restart. It acquires the dark frames again and then goes back to guiding.

 

Yes doing that. It requires the star and starts guiding. This error happens any time the telescope has to go away from the target. It only seems to happen on the first sub after doing a task such as focus. It starts guiding, then after my designated delay time of 10 seconds in CCDAP the main camera starts and then instantly the guider says guide star fade and it loses track of the guide star. It sits there for a while but eventually wanders off.

 

I have what sounds like the same problem - the AO-X is able to acquire and track the guide star just fine until the main camera starts an exposure whereupon it instantly loses the guide star saying 'guide star fade'. It does seem to (sort of) get the star back but the counts stop updating properly and it stops moving the mount when needed, eventually losing the star completely since it no longer moves the mount. I've tried various exposure delays but it does not seem to have any noticeable effect. I've also tried various permutations of multi-threading to no avail.

After it initially loses the guide star at main camera start, I am able to get it going again manually using the Maxim UI by stopping it, taking a full guider frame and restarting tracking. When I do this it seems to work fine for the rest of the exposure. Doing everything in Maxim (no ACP, no API use) works fine.

This indicates to me that the hardware and software basically works but either I've not configured something correctly or there is a bug somewhere related to main camera startup using the Maxim API. Given that I'm using ACP and need to use the API, this is a serious issue for me. I've had to give up on the AO-X until this can get addressed.

What is strange is that there are other people here running the same hardware (STXL-11002, FW8G, AO-X) who do not have this problem. I believe they are all running older firmware and pre-V6 MaximDL. I suppose there could be other differences that I don't know about.

The seeing here is excellent and my mount tracks very well so I don't think it should be losing the guide star - certainly not the moment the main camera starts.

So, I have some questions:

Is this a known issue? Do you have any suggestions for things I can try to get this working? Assuming this is not pilot error on my part (!), is there a set of SBIG firmware and MaximDL where the AO-X works properly (via the API) that I could run until such time as the current releases get more stable?

 

I am experiencing what sounds like the same problem. I'm running an AO-X, STXL-11002 and FW8G using MaximDL and ACP. It seems related to using the MaximDL API to acquire images.

The AO-X is able to acquire and track the guide star just fine until the main camera starts an exposure whereupon it instantly loses the guide star saying 'guide star fade'. It does seem to (sort of) get the star back a short time later but the counts stop updating properly and it stops moving the mount when needed, eventually losing the star completely when since it doesn't move the mount when the AO deflection gets too big. I've tried various exposure delays but it does not seem to have any noticeable effect. I've also tried various permutations of multi-threading to no avail.
After it initially loses the guide star at main camera start, I am able to get the AO-X going again manually using the Maxim UI by stopping it, taking a full guider frame and restarting tracking. When I do this it seems to work fine for the rest of the exposure. Doing everything using the Maxim UI - no ACP so no Maxim API use - seems to work fine.

Other people here running the same hardware (STXL-11002, FW8G, AO-X) do not seem to have this problem. I believe they are running older firmware and pre-V6 MaximDL. There could be other differences that I don't know about.

All of this suggests to me that the hardware, firmware and software basically works but either I've not configured something correctly or there is a bug in the firmware or software related to main camera startup when using the Maxim API to manage image acquisition. Given that I'm using ACP/Scheduler and thus need to use the API, this is a serious issue for me. I've had to give up on the AO-X until this is somehow addressed. (It is feeling lonely and forlorn sitting in the image train acting as a mere spacer while its neighbors have all the fun!)

So, I have some questions:

- Do you have any suggestions for things I can try to get this working? It's certainly possible I've misconfigured something. I've tried various versions of MaximDL starting with 6.08 through 6.10.1 which I'm currently running.

- Assuming this is not pilot error on my part (!), can you suggest a set of SBIG firmware, driver and MaximDL versions where the AO-X is known to work properly, when using ACP via the API, that I could run until such time as this gets resolved in the newer releases? (BTW, Santa Barbara is only a few hours drive if necessary)

- Is this a known issue? If so, is it safe to assume it will be corrected in due time?

 

I have found that doing a restart manually in Maxim ensures that all images that follow before moving the mount are guided properly and the error does not occur. I note it is interesting this problem exists in ACP too. That must mean this is a logic related issue. I had trouble in version 5 which prevented the AOX from working at all. Version 6 at least lets me get on with some imaging.

 

I experimented with this last night and as you mention, after I manually re-start the AO-X on the first sub, it seems to work for later subs. This is true even though ACP is re-starting the AO-X between subs (including re-measuring the guide star to adjust the exposure!).

I wonder what it different about the first sub-frame in a sequence? I strikes me as a little bizarre because I would think there is nothing special going on. I've not had a chance to see if it will run the whole night for multiple targets with a single manual restart at the beginning of the night. Hopefully I'll be able to test that tonight.

In any case, it's 100% repeatable for me so hopefully that means it should be possible to track it down.

 

Geoff, that sounds like a logic related problem. You should also see it repeat the problem once you go off to focus or cross the meridian.

 

It's interesting - I've found that I can get 6.08 to run the AO all night with the exception of the first subframe. I still see the usual problem on the first sub-frame but as long as I manually stop and re-start the AO (no need to get another full guide frame, BTW) it will run all night, even changing targets, doing meridian flips, etc. I suspect I've simply hit on a group of settings that avoids whatever timing problems exist. It's not stable though, as I've seen Maxim both crash and also lock up.

I cannot get 6.10 to work at all via the API. It loses the guide star on every subframe.

 

You probably know I am at Diffraction/SBIG this week... Not that this is the solution but it needs to be done in any case. Your problem is not universal, I now know that most people are finding the AO-X working, and that the ones with problems have the ST-X cameras. A new driver and firmware package will be released in days not weeks. Let's start with that. Be sure the version of the SBIG driver checker 64 itself is up to date as well before you use it to download and update the driver and firmware. Maybe you already know this ha ha...

NOTE: During the firmware update the thermometer will appear to freeze and the app may show "Not Responding" ... Do not lose heart. Wait it out.

PS: I am answering this because Geoff is an ACP customer...

PPS: http://www.diffractionlimited.com/f.../AO-X-gives-guide-star-fade-in-Maxim-DL.1478/ shows one customer where driver/firmware update solved his issues.

 

I am running a firmware and driver that is newer than the latest released version. Adam R. at Diffraction installed it on my system a while back.

Hopefully the next release package will get me working.

 

Bob I am doing likewise. My firmware is 2.45 and the driver is listed as newer than the latest drivers. Adam did the firmware and driver update a few months back.

 

The upcoming release will be "new". Adam is committed to getting this right. There is a new issue that we will be looking at so it may be a few more days.

 

So Adam do you think it is worth updating the driver?

 

The latest build (9) seems to have resolved the issue with the filter wheel problem connecting to the camera. I still see the same issue with the fade when the main camera exposure starts.