Samsung SyncMaster 540N User Manual page 25

RGB IN port
Kensington Lock
See Connecting the Monitor
of the monitor.
Connect the signal cable to the 15-pin, D-sub port on the back of your
monitor.
The Kensington lock is a device used to physically fix the system to
something when using it in a public place. (The locking device has to
be purchased separately.) For using a locking device, contact the
place of purchase.
for further information regarding cable connections.