Hello Andrea, Here is the link to the deployment guide for an ME4.  If you look on page 18 it explains and shows you how you want to cable your expansion enclosure.  [URL] To connect just a single expansion enclosure all you need to do is to connect one cable to each controllers expansion port, & the other end to the expansion enclosure.   Please let us know if you have any other questions.
Hi guys, we have bought a powervault me4 with one expansion. So, I saw the admin and technical manuals but i can't find any information how to connect only one expansion (the documention cover only more expansion). Can i use any port of expansion (except B port) like san controller 1 -> expansion port A  and san controller 2 -> expansion port C? thanks Andrea  
connect expansion to powervault ME4