I need to decide about how to connect two custom designed electronic units. One is main (execution) unit, and the second is hand-controller unit. Those units have to be connected by wire. The communication between units require 3 twisted pairs (for data transfer) and power supply lines (VCC and GND). The power lines are needed for hand-controller supply from the main unit. The power supply is 6V with max current consumption of 500mA. The distance between main unit and hand-controller is up to 3 meters. The perfect solution would be to have individually shielded twisted pairs.
At the first, I was thinking about RJ45 connector and CAT cable, but I am not sure about current rating. In that case I would use one twisted pair for power supply and the rest of 3 for data transfer. It seems as not reliable option for powering. There is also combination of CAT cable with two additional power lines, but it would require two connectors, so not pretty elegant solution (prefer to stay within one connector). Additionally, I need robust connection as the hand-controller would not be stationary.
What do you suggest that could be suitable for my application? The connector size is not much important. I just need to be sure that I can find also the proper cable for such connector. It is also not important if it is not exactly the right fit (e.g. have 1-2 twisted pairs more than I need).