If you use what is called 'Standalone' mode (the manual for RFX9400 is in the files section), there is an ad-hoc network created between the Pronto and the Extender and the Pronto can communicate with at most 1 extender.

If you go the Wifi route and don't use 'Standalone' mode, the Pronto, and all Extenders are devices on a 802.11b Wifi network and the Pronto can communicate with multiple extenders.

So, if you want to run IR emitter wires between several rooms, you can use a single extender. If not, then you'll be looking at multiple extenders.

Please take some time to read through the manuals as they outline alot of this stuff.

I might also suggest the Philips whitepapers here.

[Link: files.remotecentral.com]