If you want your BS5500 as a local source in a linkroom, you can do that using a Beolink active (with IR eye) in the linkroom, where your BS5500 is located and connect the Powerlink out to Audio Aux Link in of the BM5500. You will need a special cable.
Set the BS5500 to A.OPT 1 (or 2) and BL-active to L.OPT 4.
Now you can control your BS5500 by RADIO, CD, TAPE, PHONO.
And you can control your BS9000 by pressing LINK-RADIO, LINK-CD...Press first A.AUX to power up the BM5500 and activate the audio port.
BV7 can be controled in the same way: LINK-DTV LINK-V.MEM....
Maybe it even works with a BL video connected to audio aux link of your BM5500. If you press CD, BG5500 will start. If you press LINK-CD, BS9000 starts up. Video sources in the main room can be controled just by TV, DTV...ATTENTION: this works with my old (one way) BM4500, but didn`t work - unfortunately! - with my BM7000.
Stefan