USB2 - USB3 query

[bomberbaz]

Hello all.

I have on my imaging rig the guide scope currently using a USB3 cable but into a USB2 A port.  The USB3 cable is long and even when tied up makes the whole thing a little untidy.

I have a USB2 short cable with a right angle B fitting which would be far tidier, however the camera has the USB3 B type socket fitted. (This USB2 cable came with the camera btw)

I know it should work but will using a USB 2 B plug in the camera USB3 socket affect the results at all.

TIA

Steve

[barbulo]

I use both imaging and guiding cams in USB 2 ports with no issues. Unless you need a high data transfer rate (video for planetary), it should work.

[Carbon Brush]

Hi Steve.

The difference between USB2 & 3 is data speed, as @barbulo has said. The plugs are physically the same. As you have discovered.

Given that decent quality cables are a tiny proportion of the cost of cameras and other stuff, why not just buy a good quality USB3 lead in the length and configuration you want?

If your camera and the other end of the link try to run at USB3 speed, and the cable isn't up to it, there will be intermittent errors.
A few £ spent vs nights of frustration with kit not doing what you think is another argument in favour of spending.

HTH, David.

 

[bomberbaz]

6 minutes ago, Carbon Brush said:

Hi Steve.

The difference between USB2 & 3 is data speed, as @barbulo has said. The plugs are physically the same. As you have discovered.

Given that decent quality cables are a tiny proportion of the cost of cameras and other stuff, why not just buy a good quality USB3 lead in the length and configuration you want?

If your camera and the other end of the link try to run at USB3 speed, and the cable isn't up to it, there will be intermittent errors.
A few £ spent vs nights of frustration with kit not doing what you think is another argument in favour of spending.

HTH, David.

 

Yeah good point well made. See if there is such a thing as a 6 inch version ideally. 

[iapa]

Shortest USB 3 A-B I found was https://smile.amazon.co.uk/dp/B09FJ8CGH3/ref=sspa_dk_detail_1?psc=1&pd_rd_i=B09FJ8CGH3&pd_rd_w=O0lSK&pf_rd_p=a8d38b47-cfdf-4208-95a0-1af779cb6e7d&pd_rd_wg=4IdQH&pf_rd_r=R39XCZDPCBG06TE9E5K7&pd_rd_r=3231ec75-8fa5-406f-8d00-a1f68e63edab&s=electronics&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFWWVJaQkpHR1VaOVYmZW5jcnlwdGVkSWQ9QTA2NDQ0OTc0T1c4RUQ4VlQzQkcmZW5jcnlwdGVkQWRJZD1BMDM3MDM1NjJOQlVLUTdIN1ZDNTkmd2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWMmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl

 

[malc-c]

As others have mentioned, USB3 has a faster data transfer rate, on paper around 10x faster (USB2 is around 480Mbps, USB3 is quoted at 4,800Mbps).  If a modern camera has a USB3 port plugging it in to a USB2 port could create a bottleneck (best analogy I can think of is when lanes get closed on a motorway and the traffic bunches up but continues to move through the obstruction at a reduce speed).  As David has said, just look at getting a USB3 cable of suitable length and use USB 3 port on the computer.   

[bomberbaz]

I should have mentioned there are only 2 usb3 ports on the ASI AIR+ and these are occupied by the imaging camera and the mount. Really think it would be better with a third. 

[iantaylor2uk]

I think most people plug the mount and the guide camera into the USB2 ports, and the USB3 ports are often used for the main camera and the memory stick. 

If your ZWO main camera has extra USB ports on, you can also use those (I plug the EAF into one of those, but you may also be able to plug in the guide camera too). 

If you save images to the memory card rather than the memory stick this would free up one of the USB3 ports.

Edited May 9, 2022 by iantaylor2uk
typo

[malc-c]

The mount can be connected to a USB2 port.  There is not a lot of traffic between it and the computer.  Guide camera's typically have less resolution than main cameras, but they are typically sending short exposures of around 1-2sec, so USB3 would be more suited.  Likewise with the main camera as whilst the exposure may be longer, the resulting data send to the computer will make use of the greater bandwidth.

[bomberbaz]

Thanks for the replies folks.

I have switched the cables around so both cameras will be using USB3. I will store info direct to the AIR+ memory and transfer data to a USB stick after my sessions end. (I had noticed the lag in data uploading but never twigged it was the USB speed)

Finally I have ordered some shorter cables to tidy it all up.

Steve

[iapa]

One thing I seem to have missed if which cameras you are using, and what you are connecting them to.

[bomberbaz]

New cables arrived already, very pleased with end result