Hi, I have just installed a Panasonic 612. I know it has 8 digital extensions as standard and 4 XDP's. Its been a while (years) since I had anything to do with these. I have wired the blocks within the system and then presented the extensions to a patch panel, blues to blue / oranges to the greens etc etc. All this works fine. however i'm a bit confused as I only get 6 extensions ??? How do I get the other two digital extensions????? Thanks in advance. (is it to do with block 5-8)