The problem isn't the number of stations because in any case the operator must to be close to the station with the collector to take the data and this will be a peer-to-peer communication. When the operator comes to the office, he can download the data collected from the stations in a PC.
The problem is that the controller inside the collector must implement a double roll irda interface. Whe the collector take the data from stations the collector is a primary device and the station is a secondary device. Later, when the collector go to download the data in to the PC, the collector will be a secondary device and the PC will be a secondary device. This is what I mean a double roll irda controller.

Please let me know if I explain myself. Thanks

Roberto Muñoz