I realize that I am coming way late to the party here but I would like to add some additional info for others that may still read this post.
SAABoholic is exactly correct with his explanation but there is a bit more to it....
The ABB S4Cplus controller comes in two models--M2000 and M2000A: (1) M2000 [about waist high ((37 inches)) with a swing open front door and lift up top lid. All robot cable connections are outside left wall when viewed from front - there is also an optional upper cabinet extension that eliminates the lift up top lid and now becomes two swing open front doors] (2) M2000A [The M2000A was designed for Automotive customers but now flood the market as Auto companies sell them off - same guts just different architecture. Taller ((about 5 feet)) and has only a swing open front door with swing out cage behind it. All robot cable connections are at the bottom front of the controller.]
As far as the robot arm Type goes....SAABoholic above has it right but, if the sticker on the back of the arm has been scrubbed off you can still find out by making a BACKUP and you will find the info in the 'Backinfo.txt' file under the Backinfo folder. The ABB IRB4400 has only two types A or B. Type A has 'Elmo' servo motors and Type B has 'Yaskawa' motors.