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Transmitting USB signal via a slipring, connection issues.

Tags:
  • Power Supplies
  • Connection
  • USB
  • Peripherals
Last response: in Computer Peripherals
January 10, 2013 4:40:18 PM

Hey!

Here's the issue:

We are trying to gather measuring data from a rotating object. The measuring sensors and equipment are mounted next to said object and are rotating aswell.

Therefore we have to somehow supply the equipment with power and a data connection. We have a high quality slipring available and connected our equipment to the PC/power supply with a pretty rudimentary cabling job.
(Pretty much just cutting the cables and attaching them to the slipring using luster terminals.)
Anyways, this works just fine for the power supply, yet on the data connection (USB 2.0) our PC will detect a plugged in USB device, but is unable to identify it correctly.
I suspect either too high latency times or too much noise in the connection, due to the cabling. The next step would be to get unassembled USB plugs and solder them directly to the data cable attached to the slipring. This cable seems pretty standard, it contains 4 separately insulated copper strands (not twisted and of slightly larger diameter than the original USB wires) and EM shielding.

My concern is that we may have overlooked some detail, which could prevent this setup from working. If you have any tips or observations, maybe based of previous experience or an alternate solution to transmit the data, I would be grateful for all useful input!

Thanks in advance

More about : transmitting usb signal slipring connection issues

January 10, 2013 9:27:59 PM

There will be a lot of noise due to the slip ring. One way to get around that is to make sure the sensor is only connecting at USB 1 speed (12Mbps), and not USB 2.0 speed (480Mbps). To do that find an old USB 1.0/1.1 hub and connect your PC to that and then the cable going to the slip ring.

Also, you might want to make sure the sensor is getting clean enough power by adding a small electrolytic capacitor across the power leads.