max USB cord length and connecting RBK to control computer

[Greybarn]

I am sure this has been answered before but I can't seem to find any of threads. I am wondering what the allowable length for the USB cord should be between 1) the hub and a RBK control box, 2) the hub and the control computer; and 3) the control computer and the RBK control box.
And what is the best way to connect the RBK control box to the control computer. Right now I am running 3.6.46 with an old XP computer. I assume the 3.6.46 wants a powered hub. I think I understand that 3.8.XX does not need the hub. Is that correct?
Thanks for the help.
Regards
Peter

[steve_g]

USB Cable Length Limitations: The USB specification limits the length of a cable between full speed (or high speed) devices to 5 meters (16 feet 5 inches) and for low speed devices the limit is 3 meters (9 feet 10 inches).

[Greybarn]

So, now I am confused. For full speed devices we can go to 5 meters but for low speed devices we are limited to 9 feet 10 inches....Seems backwards to me.

[Greybarn]

Ok. I have read some more and now understand. I think, with USB 2.0. that I should be good with a 5 meter cable. Or put another way, I am going to give it a try. I will let you know how it works out.
Regards
Peter

[ntraub01]

Peter, we have an RBK control box and have greatly extended the USB control line from the control box and have also replaced and greatly extended the VFD control cable. Both of these cables were way to short for our needs and we've had no issues. HOWEVER, I can't tell you at this time how long those cables are but will check in the morning and let you know. I even have an extra USB cable still in the package, will take picture and post.

[Greybarn]

Ok. Thanks. I would be curious about your setup. I have a new usb cable that is 5 meters long and am going to buy a new hub. After going to the RBK, I am have some chatter on the corners which I am currently attributing to either the hub or the computer. Trying the cheap route first. I am off for some vaca so will check when I get back on the 12th

[ntraub01]

Sorry for the delay, an apparent sinus infection has kicked my butt for the past three days but alas here is the info.

We are using a USB 2.0 Active Extension Cable of 33 feet long, made by Tripp Lite (model: UO26-10M). It is hooked up to a USB 3.0 socket and we've had zero issues with it since installation nearly two years ago. I believe the key to the whole show is that it is an ACTIVE extension cable. We've had it both direct connected to the laptop as well as into a USB hub but trying to eliminate as many possible forms of error connecting it directly to the laptop has been adopted.

Until recently we've also been using an active/powered USB hub which has work well. We've since started using a wireless network in the shop eliminateing the need to use USB jump drives but we had zero issues with it as well.

We also replaced the VFD wire with a standard RJ45 CAT5 cable and extended it with something like a 25' patch cable. Yes, we don't need all of the conductors in a CAT5 cable but seeing how cheap and inexpensive and quality controlled standard CAT5 cables are we opted to just use what we had available. We've had zero issues using the CAT5 cable as well for nearly 2 years.

Can not over emphasise how important ground your machine can be to keep all of these electronic components working correctly without error.

Hope some of this helps...

Nicholas

[Greybarn]

Thanks for the info. I will take a look at an active extension cable, and let you know how it works out.