Power Panels have a CF card that holds the program, so if your unit does not have a CF card in it, it doesn't have a program in it and will only boot to the hardware/firmware screen. Some can run in terminal mode without a CF card and upload a visualization from another B&R PLC over ethernet; these are typically PP120s or mobile panel 180s.
The way you make a backup of the program is to take out the CF card and use Runtime Utility Center (included with Automation Studio, also available separately from B&R as a free download). There is an option to make a image of a CF card, as well as an option to burn a new CF card with an image you've already taken.
If your unit does not have a CF card slot, then it probably isn't a power panel (I am unaware of any power panel part numbers that have no CF card). Since you're talking about RS232 and PCIMA, I'm guessing you have something older, like a Provit display (all power panels should have an ethernet port standard, so RS232 would be a strange way to program it).
EDIT: I should point out that B&R does not store the source code on a PLC by default, so if you're talking about uploading the program to store a copy of the program logic, that's probably not going to happen. If the source code was stored on there, it was either manually placed in the F: partition of the CF card (you can download it with an FTP client when connected to the PLC) or stored as a .br file that can be loaded with Automation Studio when connected to the PLC (just use File -> Open -> Load from target).