lock up with 60 second frame using Altair 26C

[maclean]

hi Robin,

I was testing a new Altair 26C I received last week and think I may have triggered a bug either in SharpCap or maybe in Altair's underlying API. I did sensor analysis on the camera and started taking a sample dark frame at fixed intervals just so I could understand how the camera behaves.

When I tried taking a frame of exactly 60 seconds in length, SharpCap would stop downloading images and I see negative time in the status bar until I stop, close the camera, and re-start it. Initially, I was worried there was something wrong with the camera, but eventually I discovered that I could run either 59s or 61s and it worked fine. All my longer frames (120s, 180s, 240s, 300s) also worked fine, so I'm thinking this is just a software bug. I attached a log for you where I took a 59s image (successfully, from 16:10:48-16:11:47) and then a 60s image (unsuccessfully, from 16:11:59-16:12:59) which does not download and I canceled the capture about 90s later. I noted there is an Exception of some sort recorded with the successful 59s frame; I don't know if that means anything, but the image was downloaded and written to my drive. I did this particular test with the 3.3beta since it had the newest build date (I know it's a very new camera), but I got the same behavior with 3.2 also.

For now, I know just not to try to capture exactly 60seconds, so it seems to be an easy thing to avoid, but I thought I would report it in case it is useful. I also noted that my 26C in SharpCap only gives the options of USB=0,1,2 in the interface, but it is registering in my system as a USB v3.1 device. This doesn't matter at all obviously for DSO imaging, but I thought I'd mention it also.

Let me know if you want me to try anything - I'm happy to test since I know this is a new camera.

Matt MacLean
NY (USA)

[admin]

Hi Matt,

yes, I've heard about this issue from the manufacturer and actually I had an email from them today with a software update that should (I hope) resolve the problem. I hope to have an update out in the next few days.

cheers,

Robin

[turfpit]

Matt

I also noted that my 26C in SharpCap only gives the options of USB=0,1,2 in the interface, but it is registering in my system as a USB v3.1 device

Altair cameras present a USB Speed Control setting which can be 0, 1 or 2. These figures do not relate to the level of USB bus available.

Use the highest setting which does not drop frames. See page 5 of my document viewtopic.php?f=35&t=2590. The example is an Altair 183C which is USB3 and was connected into a USB3 port on the laptop when I ran the tests.

Dave

[maclean]

Thanks guys. That all makes sense. I'll look out for an update.