E220-900T30D. Remote monitoring of objects.

Hello. I am developing a system for displaying events from remote objects to control door limit switches (alarm). I plan to use Arduino MEGA with a large number of input/output channels on the receiving side. These channels will be used to output alarms (LEDs) to the receiving device panel to display discrete information. Arduino UNO or NANO will be installed at remote objects, which will receive signals from the limit switches. The total number of controlled objects is 6. In the figure, I have schematically shown the operating principle of my system. Tell me: 1) Which settings modes (receiver, transmitter) are best used when building such a system? 2) How should I process incoming information from remote devices on the receiving device so that the desired LED lights up when an event occurs? If I use only one receiver and transmitter, then the event transmission occurs without problems. But how to process data from several devices I do not understand. Thank you very much for the library!