D-Link DKVM-IP8 User Manual page 14

Press "↓" to control next PCs untill 8th/16th port. Press "+" to
controll second level PCs. If you would like to back the first
level PCs, please press "-" when OSD show "0.1 SERVER-01"
Note: Each products need to connect power when cascade, the
product of each input port can be used as a cascade port,
cascaded up to two level. (Cascade will account for an input
port)
8 port cascade diagram
LAN port
(Only the first
level can be contected.)
The
first
level
The
second
level
The
second
level
Note: 8 port KVM switch connect up to 56PCs
VGA
KVM
cable