Just give each panel a unique number, starting with Panel1, Panel2, Panel3 and so on. Then you can use the intrinsic reference scheme, its the simplest and most basic of referencing in the system. It works over Ethernet too.
10 VAR1 = 2IN1
The only time you need to mess arround with the 2.2 notation is when you are mixing references from the main ethernet network to RS485 subnet devices. Here is a link describing all the possible Ethernet/RS485 and bacnet/modbus scenarios.
Note: Subtle point here but you dont actually need the END statement, the program will run to the last line of the program and loop back to the beginning just fine without it.
