If two systems were installed within range of each other a button press on one remote would be seen on both systems if they shared the same device ID.

Try this just to see what happens. Bring a T2-c or other RTI remote on site, load a previously used program to it with an RP1 in the file. Start pressing buttons on the new remote, you should see the installed RP1 light up and some of your button presses will do things to your installed system.