Need some help on this one - drove me crazy last night. Everything proceded normally with CCD Autopilot at first but started getting "unhandled exception messages" during the plate solving process. It did not have the error every plate solve, just on some of them. After I gave up on the light frames, CCDAP took an entire bias, dark and flat sequence without the error. I would appreciate any insight you could give me as to the cause of this error. I have been using CCDAP for some time and have not seen this before. I have already uninstalled and reinstalled CCDAP. May need to do the same with CCDSoft. Need some insights on this, as I hope to test again tonight.

I'm attaching a log and the details from the unhandled exception that ended the run.

Thanks,

Bob English

Status_Log_110409_213140.doc (40 KB, 7 downloads)

Here is the unhandled exception details...

Thanks,

Bob English

Unhandled_Exception_2.doc (34 KB, 5 downloads)

Hi Bob,

It looks like there may have been an issue with CCDSoft being able to access your harddrive as it appears it couldn't write the file. Check to be sure that there were no virus checking routines running in the background that could have caused that condition to exist for a short time. HTH ....

Thanks, Frank, I'll check and see if the last scan (if it's shown) is during that time period. It obviously was a transient effect of some type. But this will help me narrow things down. I hope it's something that simple. I'll be checking things out again tonight.

Bob English

Hi Bob,

Command failed in the log typically indicates the failure of the automation interface of the server application, CCDSoft in this case. See the Help file, Troubleshooting/Techniques, "When things don't go as expected". I suspect there was another instance of CCDSoft running.

Hi John,

Thanks for your help. My CCDSoft program had been doing some odd things, so I uninstalled and reinstalled it. Seems to have corrected the CCDSoft problems. Imaged last night and everything was going perfectly, including the meridian flip, and then I suddenly had an exception. This time I had lost my connection with The Sky. I could not reconnect, so I may have a cable problem. I don't think the problem is related to CCDAP, as it seems to be doing a great job. My problem solving right now is centered around my connectivity problems with The Sky. Odd, because I've never had the problem with my Gemini before.

Bob English

PS - Thanks for the reminder on the Help file - I'll spend some time with it today.

Bob

Hi Bob,

Glad you are operational. Yes, it could be a cable or a USB hub if you are using them. Most hubs you buy at OfficeMax and the like are intended for indoor use with limited temperature range, typically 10-35C. As nights get cooler, hubs can get flaky.

A little feedback - the problem did turn out to be the cable from my Gemini controller to the computer. The cable plugs into the Gemini with a RJ22 plug that has a female DB9 9-pin plug on the other end. The metal clamp that's supposed to relieve the pressure on soldered joints was too big for the cable and one of my small wires had come loose. Soldered it back and everthing connected up again. I also altered the clamp so it snugged up to the cable.

One question: I'm attaching a log from a test image last night. The guide star was bright (9th mag) and the image guided perfectly. But the ADU measurement on the guide star shows less than 2,000. I'm used to seeing around 15,000 on a guide star this bright. The system's working fine, but why the change? Normally a 2,000 ADU guide star is guaranteed failure. Some scaling problem somewhere?

Thanks,

Bob English

ccdap20091106_204946.log (14 KB, 8 downloads)

Glad you found the cable issue.

Your guide exposure is a very short 0.4 sec. To avoid chasing seeing, I use a minimum guide exposure of 3 sec. At 3 sec, 1900 ADU would equate to 14,000 ADU, which is about right for what I see and use here.

If you look at the peak value of the guide star in CCDSoft, what does it indicate at 0.4 sec. guide exposure?

On checking some of my past logs I see that the ADU measurement is not that different than what I was using in the past. I'm sorry to raise a false issue. My memory was playing tricks and adding a zero, I guess.

I use an AO8 adaptive optics unit, which is why I have used fairly short exposures. Typically, I can make long (20 minute) exposures without the telescope mount being called upon to make any corrections.

However, 0.4 second is not fast enough to significantly reduce any real seeing-related movements. I will experiment with some longer exposures. Your guiding algorithm works very, very well.

Bob

Hi Bob,

Sorry, I didn't realize you were using an AO. That changes most of what I said Guiding will always be better moving a couple of oz. piece of glass (in the AO) a little bit than trying to move a heavy mount. 0.4 sec. (or shorter if you can) is great for guiding. Even if you can't guide fast enough to get first order seeing corrections, you can be sure your guiding will be a lot better than through the mount.