Moving from a PanelView 550 to a PanelView 1200e is possible, but it is not a seamless transition. Here are a couple of reasons:
1. This shift requires you to purchase different PanelBuilder programming software. The 550 uses PanelBuilder32; the 1200e uses PanelBuilder 1400e software.
2. The difference in screen sizes will mean that you will have to do some work with each screen in your application to make the screen size work. I don't believe there's a utility in PanelBuilder 1400e that automatically converts the program to the different screen size (I'm more familiar with RSView ME, which has this feature; perhaps another AB guru will know if this feature exists in the earlier software.
Regarding RSLogix 500, the ladder program you created for your 550 application should work with the 1200e, provided there is not a change in the tag names, etc. when you make the switch.
Hope this gets you started!
Rick