Dell PowerEdge C6220 Hardware Owner's Manual page 216

Here takes 24 x2.5" hard-drive configuration as an example to show the
cable connection between middle plane and hard-drive backplane.
Figure 3-70. Cable Routing−Top Middle Plane to Backplane for 24 x2.5" Hard-Drive
Configuration
Item Cable
Hard-drive
backplane
cable
Hard-drive
backplane
cable
216 | Installing System Components
From
(Top Middle Plane)
mini-SAS connector for
system board 1 and 2
(hard drive 1,2,3 and 4)
(J1)
mini-SAS connector for
system board 1 and 2
(hard drive 5 and 6) (J2)
To
(Backplane)
SATA2 hard drive
connectors 1 to 4 for
system board 1 (from
right to left)
SATA2 hard drive
connectors 5 to 6 for
system board 1 (from
right to left)