Samsung LS19MBPXFV-XAA - Manual (Page 14)

DVI :
Connect the DVI terminal of your monitor to your computer using a
DVI/D-Sub cable.
DC 12V :
Connect a power line to a direct current power supply and then plug
it into the relevant power port.
UP (USB upstream port):
Connect the UP port of the monitor and the USB port of the
computer with the USB cable.
DOWN (USB downstream port):
Connect the DOWN port of the USB monitor and a USB device
with the USB cable.
z
To use DOWN (Downstream Port), you have
to connect the UP (Upstream Cable ) to the
PC.
z
Make sure to use the USB cable supplied with
this monitor to connect the monitor's
UP port
and your computer's USB port.
See Connecting the Monitor for further information regarding cable connections.