ASI cameras and USB

[ian_bird]

ASI cameras and USB

I have just bought an ASI 224 camera.

It works plugged directly into my laptop.

But when I add an extender cable or hub - forget it.

I know it says on their web site "Don't use with a hub or extender cable" but that is just riduculous. What - I have to park my laptop 5 feet away from my telescope? Come on!

My setup runs USB connections back to my shed for the focuser and mount. So I need the ASI to work there too.

I have tried with a powered USB hub and a powered extension cable (5m length). And the ASI won't play!

Has anyone else had this problem?

Cheers.

Ian

[jsmoraes]

Yes, I had. Now I am working with 3 meters cable, without hub. And it only works with only one of my 3 USB ports of my netbook.

My net has 3 USB ports. 2 are with internal hub. So I have only 2 independent USB port. I must work with the port that hasn't internal hub.

I must to adjust the USB traffic slider around 60 to 70 %.

My great problem with my ASI is that it captures more than effectively it transmits to computer. There are different number in captured frames and dropped frames. As the AVI movie can't stop... some frames are repetition of the priors frames. I  think that I did 1000 frames, but actually I have only 500 - 600 different frames.

[JamesF]

The camera is somewhat different from the focuser and mount in that it is streaming large amounts of data across the USB connection.  If the frame rate is high that may place limitations on the total length of the cable or on the technical capabilities of a hub placed in the middle.  Also, USB3 isn't guaranteed to work over a cable more than 3m long at all (from memory).  As I understand it the electrical specification of USB3 means that longer cables cannot be relied upon to work.  Some people have managed it, but there may be a certain amount of good fortune involved.

That said, I have just plugged a USB3 ZWO camera into my Orico USB3 powered hub using a short (30cm-ish) cable.  The hub is connected to the PC with a cable about a metre long.  The camera appears to work fine.  Obviously you require cabling somewhat longer than that, but clearly the "don't use a hub" restriction is not absolute.

James