12 replies to this topic

[cchivers]

Hello -

 

Just purchased a few "nylon braided" USB cables to use this winter, as the PVC sheathed cables become very stiff in the cold.  Since using these cables though, I've started getting these bad images randomly about 1 in every 25 images, and I'm guessing the cables are to blame - has anyone seen this before?

 

https://www.cloudyni...or-maybe/large/

 

I really like how the braided cables stay flexible in the cold, but if this is a result of the cable, I'll ditch them in a heartbeat...

 

Thanks,

[Andros246]

Hello -

 

Just purchased a few "nylon braided" USB cables to use this winter, as the PVC sheathed cables become very stiff in the cold.  Since using these cables though, I've started getting these bad images randomly about 1 in every 25 images, and I'm guessing the cables are to blame - has anyone seen this before?

 

https://www.cloudyni...or-maybe/large/

 

I really like how the braided cables stay flexible in the cold, but if this is a result of the cable, I'll ditch them in a heartbeat...

 

Thanks,

Wow i've never seen anything of the sort.

Edited by Andros246, 04 February 2023 - 01:05 AM.

[AaronH]

I saw similar images with my QHY163C when I had my PC mounted on the tripod, and long cables running up to the OTA. The corrupted images were intermittent, worse some nights than others, and just when I thought I'd resolved the issue, they would appear again.

 

I never really resolved whether it was due to issues with power delivery or data corruption on the long, thin USB cable running to the camera. In the end, I addressed both at once by mounting a Pegasus Power Box Advance on the OTA. That resolved any power issues and allowed me to run a short, sturdy, high-quality USB cable to the camera from its powered hub.

 

The USB subsystem of the QHY cameras really seems to be intolerant to data corruption. The shorter and better-shielded the USB cable, the better.

Edited by AaronH, 04 February 2023 - 01:53 AM.

[gsaramet]

I saw that in two situations, both not related to astro. Anyhow, here they are, maybe it could be helpful:

 

1. bad memory card on a camera. Was not reported as bad and was randomly creating this kind of artifacts. 

2. bad "special" USB3 driver - when USB3 was new. I think it was a driver or program made either by the producer of the external disk or motherboard which was supposed to keep up the USB3 transfer. Same, when copying many images it would randomly create this kind of artifacts. **** thing worked when copying big files or few files.  System worked perfectly without the driver, as I found out when troubleshooting. 

[davidmalanick]

Hello -

 

Just purchased a few "nylon braided" USB cables to use this winter, as the PVC sheathed cables become very stiff in the cold.  Since using these cables though, I've started getting these bad images randomly about 1 in every 25 images, and I'm guessing the cables are to blame - has anyone seen this before?

 

https://www.cloudyni...or-maybe/large/

 

I really like how the braided cables stay flexible in the cold, but if this is a result of the cable, I'll ditch them in a heartbeat...

 

Thanks,

QHY lists this problem as a bad USB connection/cable. It's happened to me with a bad/cheap cable. Also, if the cable is loose and not seated properly it will show frames like this randomly.

[Relic]

Same as davidmalanick, I have had that with my QHY268C a couple of times awhile back. Better cables and good connections fixed it.

[cchivers]

Agreed, all symptoms point to a bad USB cable.  I have a StarTech powered USB hub *rugged industrial rated, and it has been working flawlessly since install.  All other USB devices in my rig (iOptron mount, ZWO focuser, Starshoot autoguider camera) are working fine, and in addition those all use shorter, apparently better made, cables.

 

The cable to my QHY is the longest run and moves the most during my imaging sessions - I'll swap it out with a premium braided cable and test further.

Thanks for the feedback!

[JF1960]

I would make sure to try updating all your software and drivers.  You’d think a bad USB cable would give you transfer errors.   Serial protocols have error checking built in.  So it can’t just semi work.   Those images look like the software is screwing up and putting things together wrong.  Was the old cable a USB 2.0 cable?  If so, that was maybe masking the SW errors before.

[rgsalinger]

Your hub belongs on the OTA if possible. That would make any cables between hub and camera no longer than a couple of feet at most and will, I think, eliminate your issue entirely. You can use a USB2 cable as I do when USB3 gets flaky. The difference in download time is very small if you do the arithmetic and the difference in reliability can be large. 

 

Rgrds-Ross

[Robert7980]

I would make sure to try updating all your software and drivers.  You’d think a bad USB cable would give you transfer errors.   Serial protocols have error checking built in.  So it can’t just semi work.   Those images look like the software is screwing up and putting things together wrong.  Was the old cable a USB 2.0 cable?  If so, that was maybe masking the SW errors before.

Not necessary, it depends on how the driver is doing the transfers... All the OS will do is enumerate the devices, after that you can send data wrapped w header however you want, RS232, ASCII, TCP/IP ect, the error checking of the data in the frame is left to the consumer protocol stack, and it's pretty clear that QHY didn't bother with it, probably to increase overhead and framerates or just lazy... You'd assume there'd be at least a checksum though...  

[AaronH]

I would make sure to try updating all your software and drivers.  You’d think a bad USB cable would give you transfer errors.   Serial protocols have error checking built in.  So it can’t just semi work.

This is not my experience with QHY cameras. If the USB cable is too long, you get corrupted frames. And, sometimes, driver crashes. It seems there is a lack of error checking and error correction on these cameras.

 

When I was receiving these issues, I experienced them on both NINA under Windows and Ekos under Linux. On two different computers. Adding a Power Box with a powered USB hub and replacing the USB cable with a shorter one fixed both.

 

It's definitely a hardware-related issue. In reality, it shouldn't be. Error checking and recovery should be a given.

[rgsalinger]

We must have had about 25 threads plus my own experience that images like this have zero to do with drivers and everything to do with USB topology with one exception. If you are using USB3 then check to make sure that the bandwidth setting is as low as possible. From memory mine are set at 40. 

 

Rgrds-Ross

[cchivers]

All - thanks for the great thread and discussion.  I have replaced my cheap woven sheath USB cables with StarTech cables, same vendor as my rugged USB hub.  All issues are resolved after testing on hundreds of images/downloads over the last few nights.

 

I also have relocated my hub from the tripod to the OTA, shortening many of my cable runs and tidying up my cable management in general.

 

The StarTech cables may be PVC sheathed and will get stiff in the cold, but they're error free and reliable.  Problem Solved!

 

Thanks,

Carl