Hi,
there is a highway in configuring digital and proper slot, you can use slot 3,4 and 14 but not exceeds in 32 ports.
if you have a upo/e module it requires a ctr upo/e module.
highway 1 slot 1,2
highway 2 slot 3,4,14
highway 3 slot 5,6,7
highway 4, slot 8 9 10
highway 5 slot 11,12,13 and so on.