Hi,
I went through this a year or so ago and kind forum members helped me put this together for my phase back on the X-Act2. You need at least the rollei cable 36705 and 64878 and a maybe a special phaseone cable that has a little box with a chip in it. The cables connect together in a chain to go from the Lens Control S to the phase back. You can order the rollei cables directly from DHW or buy from B and H photo actually. I bought my phaseone portion of the cable from DSMWW. What you'd like to find is the single piece phase one cord in the first picture but I couldn't find it, so I had to piece it together with the next two cables joined together. The cable end on the black box goes into one end of the 36705 rollei cable and the other end of the rollei cable goes into the Lens Control S. You can't mess it up because the connections are different and it only fits one way. That's the easy part, the hard part is finding the phase cable. I am currently using mine now, but when I upgrade my backs I will have it for sale which hopefully will be soon!