You will get better responses to your questions at the
www.sma-america.com web-site, they have there own brand specific discussion board there
Last I knew, the sma's have NO communications bulit in, you have to add cards to do this. For powerline, its a modem card that goes into the SB2500 for example and then you need a sunny data at the other end to translate this from powerline to RS232 so your computer can poll the data, the cost is well over a grand for this!
The lowest cost approach is adding the RS232 card to each unit ( ~150 bucks ), but if you have the display, NO option cards can be added, though I though I read SMA was working on a combination display communtcaion card ... I'm not sure you can poll multi-inverters with sunny data like you can with GT-View so that may not work?
Again the sma web-site will be your best source for the lastest options.