What’s causing this on my qhy268m occasionally

[tim r]

See photo this happens every so often, using usb 3 from onboard hub on Ioptron 120 then straight into pc..pleas excuse the large dust moats

[tim r]

Just checked Nina setting my usb limit was set at 0 , read online should be 40 ( for Zwo)don’t know if this will stop since the change of settings I’ve had 7 more 180 subs come out ok.

dose anybody know what this setting is for , is it download speed or capacity or am I barking up the wrong tree

[Richard_]

What length USB cables are you using and what brand? The general rule of thumb is to use a good quality cables and to use the shortest cable length possible. For USB 3, do not exceed a cable length of 3m as mentioned by Pegasus Astro in the link below.

https://pegasusastro.com/cable-management-recommendations/

[tim r]

Less than 3m just about, bought a reasonably expensive one, but who knows they claim to be good .. Don’t know it’s it’s using all the usb 3 ports on the mount , going to move the Zwo guider to the usb 2 port to the left and it that doesn’t help plug the Primaluce gotto focuser into a usb2 to only run usb 3 with the camera 

[tim r]

42 minutes ago, Richard_ said:

What length USB cables are you using and what brand? The general rule of thumb is to use a good quality cables and to use the shortest cable length possible. For USB 3, do not exceed a cable length of 3m as mentioned by Pegasus Astro in the link below.

https://pegasusastro.com/cable-management-recommendations/

Thank had a good look might change somethings around

[tomato]

I’m not sure what the setting actually does, but I do know increasing it helped to eliminate a horizontal banding issue I was experiencing with IMX571 sensor cameras.

[PhilB61]

I would also try a direct cable run to your PC ie not too through the iOptron USB hub, it won't be as neat but just for elimination purposes, it's worth testing. 

[tim r]

4 hours ago, PhilB61 said:

I would also try a direct cable run to your PC ie not too through the iOptron USB hub, it won't be as neat but just for elimination purposes, it's worth testing. 

It’s looks so neat , no chance of snagging, I lost 5, 180 subs from 80 exposures, (unfortunately 3 in 1 channel) , I’ll test direct but not sure if the chance snagging is worse than loosing some images. 

[Starflyer]

Take a look here, it's a great thread about the QHY268M generally and worth a read.

[Stuart1971]

You don’t even need USB 3 cables, you get far too much interference with them, USB 2 is perfectly fine and better in nearly all cases of long exposures, USB 3 is only needed for fast frame rate capture, like planetary imaging with a ROI, give yourself less headaches and just use a USB2 cable and set the USB traffic on about 10, in saying that i use 0 on my 268 with USB 2 and it works flawlessly..👍🏻

[tim r]

4 hours ago, Stuart1971 said:

You don’t even need USB 3 cables, you get far too much interference with them, USB 2 is perfectly fine and better in nearly all cases of long exposures, USB 3 is only needed for fast frame rate capture, like planetary imaging with a ROI, give yourself less headaches and just use a USB2 cable and set the USB traffic on about 10, in saying that i use 0 on my 268 with USB 2 and it works flawlessly..👍🏻

Will try this makes sense it’s not planetary at 100 fps , lost 4 images last night out of 60 not counting cloud cover. Thanks Tim.