Schick:
I have had some experience with control and power wiring going into and out of rotating machinery; the machine was a strander, a machine which took individual copper strands (usually 19) and wound/stranded them onto one large reel. The data and power transfer was accomplished with slip rings and brushes - and this was the greatest source of problems with this machine. The power transfer was not so bad (it did not require extremely low resistance) but the data was a constant problem. Only periodic cleaning and replacement of bad brushes kept it running at all.
At the last Wire Show I attended before changing industries, the latest innovation in control of rotating machinery was on display - wireless data transfer. Power was transfered with slip rings, and E-Stop control wires, but everything else was wireless. I have noticed in my current industry that wireless data transfer is rapidly becomming more dependable, faster and cheaper; I'm thinking of wireless Ethernet in particular. A stationary PLC communicating via wireless Ethernet with a remote I/O rack ought to do the trick.
The wireless machinery I saw was manufactured by Bekeart (based in Belgium, but with plants in the US), and if you are not in a competing (wire manufacture) industry, they might share some insights with you.
That's all I've got. Best of luck.
