This is where we need more details re the 218 please.

Based on the picture in the 218 Zone Controller launched thread it has no separate comms connection or RS232 control connection so presumably the control interfaces are speakerlink in, speakerlink out (back from the master speaker in a very simple two-channel setup), the IR detector and over the network connection (as an 818 can) via Sooloos?

In the spirit of Spinaltap, I would like to confirm that I am not involved in the corrupt theft of a global sport.