You communicate with PV+ terminals via RSLinx Enterprise, which is part of FactoryTalk View Studio ME/RSView Studio ME software packages. You will need one of these software packages in order to be able to do anything with the application on the terminal.
Another important thing is the firmware revision of the terminal. If it is 5.0, you will need Factory Talk View Studio. If it is 4.0 or below, you will need RSView Studio ME. Also, if it is 4.0 or below, you will not be able to modify the file that resides in the terminal, you will need the original project (.APA file extension).
If the application is in 5.0, you can restore the file (.mer) in the terminal as long as the person that compiled it allowed it to be restored.
Clear as mud?