I use a ZWO ASI120MM-S as a guide camera and it has always worked fine. In fact I used it yesterday night for guiding with the internal guider and had no issues at all.
When I started up Ekos tonight however, the camera suddenly misbehaves. Despite being set to take 3 seconds guide exposures, it persists in taking 9 second exposures and saving them to my home folder. The real surprise to me, is that I have never set it to take 9 second exposures. I have restarted my computer (Rock64 sbc) and even physically removed and reconnected the camera. No change.
I can't find any reason for this behaviour in the INDI settings for the camera or in Ekos. So, what's happening?

I attach the Ekos log for the latest session start.

Edit: quick fix
After trying a while, the Ekos internal guider reports exposure time out and tries to restart the exposure. In the mean time, the image that was captured (!) is saved. Then the INDI control panel pops up.
I switched to PHD guiding. Only once, PHD reported a lost connection to the guide camera, but now it works just fine and it's guiding, ie with PHD, not the internal guider. This will do for now. Tomorrow I will get a new USB3 cable, just in case it's a cable issue.

CS,

Wim

I don't see the problem. According to the log, you requested 3-sec exposure, and you got it...

if the default value changes back to 9, you may want to purge the camera configuration and save a new one.

Yes, but also 9 second exposures
[2020-09-23T20:31:47.285 CEST DEBG ][ org.kde.kstars.indi] - ZWO CCD ASI120MM-S : "[DEBUG] StartExposure->setexp : 9.000s "
[2020-09-23T20:31:47.291 CEST INFO ][ org.kde.kstars.indi] - ZWO CCD ASI120MM-S : "[INFO] Taking a 9 seconds frame... "
[2020-09-23T20:31:56.870 CEST DEBG ][ org.kde.kstars.indi] - ZWO CCD ASI120MM-S : "[DEBUG] Aborting camera exposure... "

And why would it set an exposure time of 9 seconds? I just don't get it.

I don’t get it. So you set to 3 sec and on its own switched to 9 on the next capture? Or you did do something that may trigger setting refresh? Also what OS you are using?


Thank you
Mohamed

It didn't even start with 3 seconds, which is the only time I have set. It started with 9 seconds, then switched to 3 and back to 9, according to the log.
Also now my ASI174 imaging camera refuses to download images. It works fine in the alignment and focus modules, but refuses to save images in the capture module. Probably a separate issue ...
Btw, I reconbected my guide camera with a new usb2 cable, so that can't be it. And the guide camera works fine in PHD.
The OS btw, is Ubuntu 18.04. Has worked like a charm, and I haven't updated this week yet. Since it all worked flawless yesterday, I don't suspect the OS.

If I where you, I would restore a backup image, and see if the problems are gone. No OS is bulletproof. Also if you run it through RPi (as I do), there is a good possibility that the SD card is gone bad.

I’m beginning to suspect the SD card, actually. It’s a good thing I have a new Rock64pro with emmc storage incoming. I was going to use it for other projects, but will install indi and kstars on it. That should also increase speed a fair bit.

I solved this issue by brute force.
I have currently two Rock64 SBCs, one with an SD card (and which I used for INDI) and one with an eMMC memory module, which I was in the process of upgrading. I reformated the eMMC Rock64 and installed everything from scratch. Now it works. The other SBC (with SD card) will get the same treatment, so I have a back up.
I also have a Rock64PRO incoming (has just cleared customs) with an eMMC module, which I was planning to use this for other projects, but I may just make it my main astronomy controller.

I'm glad to hear that your problem is resolved. I recently ran into a bad SD card which gave me hard time even to diagnose it, until I tried a newly purchased one. The same bad SD worked fine again as a camera SD card, which makes me believe it may be a bad connector, so I decided to find a way to backup my SD cards from RPi without taking it physically out from the RPi (Hot backup) to avoid physical damage to the SD card.

SD cards are not meant to be used as solid state drives. I did an exactly identical reinstall of my system on the other Rock64, which has a SD card and not an eMMC card. During the installation of astrometry index files, Kstars crashed a few times, which I suspect was due to SD card communication errors. The only difference between a crashing system and one that didn't, was SD card vs eMMC module.

Adding to what Wim wrote, I use an external SSD to write my images to so 1) the SD card doesn't get used so much and 2) I can disconnect the SSD and connect it to my laptop to process the images.


Wouter

I thought that the normal read an write operations during program execution, were the main cause for SD card degradation, and not so much image storage. But adding a ssd for image storage makes sense.