Cost is, within reason, not much of an issue, as its use would imply the consumer would have purchased multiple, very expensive machines already. The ability to simplify data aquisition from multiple machines would also influence the company's decision to choose our machines due to ease of expandability. I would like to stick to rs232 (the standard used by the individual machine boards) because I could easily interface new machines with minimal code changes. I guess what im really looking for is a sort of "switch" IC, perhaps receiving some sort of signal to change which board the hub board would be communicating with. However, my search isnt producing much- maybe Ill check out your solution.

Much Thanks,
Ryan Killian