Camera disconnects and won't reconnect until reboot

[cyo]

Hi,

I'm seeking help to determine if this is a hardware issue or software issue.

I have a QHY 568M camera that occasionally disconnects during a capture sequence or shortly after it is connected. Sometimes the preview freezes and sometimes Sharpcap displays an error message saying the camera is disconnected.

Attached is the log for a capture sequence. The last capture file I had was at 12:22, discovered the issue around one hour later with the error message displayed in sharpcap. I trimmed some logs at the end to fit the attachment size limit.

Thank you,
Siyu

[admin]

Hi,

thanks for sharing the log. At 12:22:44.45 I can see a cluster of log messages that record the camera disconnecting from USB and then very soon after reconnecting again. These messages are broadcast by Windows when any USB device is added or removed and SharpCap records them in the log to help track down situations like this.

First we need to think about the possible causes of this happening - one possibility is a cabling problem - a loose connection perhaps being pulled by the movement of the mount leading to this happening. Perhaps more likely is an issue with the camera itself causing the camera's internal systems to reset.

Secondly there are a number of possible ways that a situation like this can be recovered....

* In the best case, SharpCap detects the disconnection and the following reconnection and reconnects to the camera automatically and everything just continues to work. There is code in SharpCap that will attempt this, but it cannot ever be 100% reliable, since errors may occur in the camera SDK or camera driver that prevent things from working after the reconnection.

* Sometimes fully closing the camera in SharpCap and re-opening will be sufficient

* Sometimes you have to close and then re-open SharpCap to get the camera working again. This often indicates that the camera manufacturer provided code (QHY SDK in this case) that runs inside SharpCap has become confused, and restarting SharpCap allows it to reset to a working state

* Sometimes an unplug/replug of the camera is required - this can indicate that the camera itself ended up in a state that was not responding properly and needed a reset to clear any problem. It can also indicate that the Windows system driver for the camera became confused, but detaching and then reattaching the device fixed the issue

* Finally, you can end up in the situation you observed where a reboot is needed - this tends to point at the QHY Windows system driver being confused by the detach/re-attach of the device, preventing it from passing on commands properly to the camera until the system is reset.

Unfortunately there isn't much here that is 'actionable' on your part (or on my part for that matter) to try to prevent it from happening again... You can check your USB cabling is all robust, and check you have the latest QHY Windows system driver and latest versions of SharpCap installed. If it happens again, you can try the various stages above to see if you can get the camera to work again without needing to reboot.

cheers,

Robin

[kaymann]

One thing I haven't seen mentioned much involves poor power cabling. When I had a good USB cabling solution I kind of ignored the possibility of poor power cabling. This is relevant to this situation because my 533MC Pro would simply refuse to acknowledge it's presence unless the sequence of power first USB second was established. For me USB and Power had to be disconnected, then power first and second USB then all was good. This situation became visible to me because a PC restart would shut down USB for a while making power first and all good when the PC booted to the USB stage. I hope I made myself clear here. It wasn't a guarantee, but it was consistent enough for me to replace my power cabling (one section I discovered had a squished center pin) and get reliable results. Just something to think about.

YMMV

[admin]

Hi,

yes, good point - some cameras may *need* the 12V power to boot up, while others seem to be happy to run (at least somewhat) on USB power. In some cases the camera may remain 'powered on' if it has 12V power in spite of a USB disconnect or PC reboot.

It's never simple, is it ...

cheers,

Robin

[cyo]

Hi,

thanks for sharing the log. At 12:22:44.45 I can see a cluster of log messages that record the camera disconnecting from USB and then very soon after reconnecting again. These messages are broadcast by Windows when any USB device is added or removed and SharpCap records them in the log to help track down situations like this.

First we need to think about the possible causes of this happening - one possibility is a cabling problem - a loose connection perhaps being pulled by the movement of the mount leading to this happening. Perhaps more likely is an issue with the camera itself causing the camera's internal systems to reset.

Secondly there are a number of possible ways that a situation like this can be recovered....

* In the best case, SharpCap detects the disconnection and the following reconnection and reconnects to the camera automatically and everything just continues to work. There is code in SharpCap that will attempt this, but it cannot ever be 100% reliable, since errors may occur in the camera SDK or camera driver that prevent things from working after the reconnection.

* Sometimes fully closing the camera in SharpCap and re-opening will be sufficient

* Sometimes you have to close and then re-open SharpCap to get the camera working again. This often indicates that the camera manufacturer provided code (QHY SDK in this case) that runs inside SharpCap has become confused, and restarting SharpCap allows it to reset to a working state

* Sometimes an unplug/replug of the camera is required - this can indicate that the camera itself ended up in a state that was not responding properly and needed a reset to clear any problem. It can also indicate that the Windows system driver for the camera became confused, but detaching and then reattaching the device fixed the issue

* Finally, you can end up in the situation you observed where a reboot is needed - this tends to point at the QHY Windows system driver being confused by the detach/re-attach of the device, preventing it from passing on commands properly to the camera until the system is reset.

Unfortunately there isn't much here that is 'actionable' on your part (or on my part for that matter) to try to prevent it from happening again... You can check your USB cabling is all robust, and check you have the latest QHY Windows system driver and latest versions of SharpCap installed. If it happens again, you can try the various stages above to see if you can get the camera to work again without needing to reboot.

cheers,

Robin

Thanks Robin! That's very illustrative.

I hate to say that I checked with some other cables and it seems to be working.

[cyo]

One thing I haven't seen mentioned much involves poor power cabling. When I had a good USB cabling solution I kind of ignored the possibility of poor power cabling. This is relevant to this situation because my 533MC Pro would simply refuse to acknowledge it presence unless the sequence of power first USB second was established. For me USB and Power had to be disconnected, then power first and second USB then all was good. This situation became visible to me because a PC restart would shut down USB for a while making power first and all good when the PC booted to the USB stage. I hope I made myself clear here. It wasn't a guarantee, but it was consistent enough for me to replace my power cabling (one section I discovered had a squished center pin) and get reliable results. Just something to think about.

YMMV

Thanks I also observed that with my 533m and I heard folks putting their QHY cameras in remote sites often have to use controllable usb hub to do this.

[admin]

Hi,

yes, a USB hub where you can turn the ports on/off to reconnect a camera is useful at any time and essential when observing remotely. I've seen cameras of pretty much all brands lock up and need to be unplugged and one point or another. If you want to have cameras that are good at avoiding this then industrial type cameras are the most robust, but are very expensive and tend not to have cooled options... Also, they have relatively poor support in SharpCap because not many astronomers use them

cheers,

Robin