Tripp Lite SmartPro SMART5000RT3U Owner's Manual page 5

Connection (Optional)
Your UPS will function properly without these connections.
DB9 Port Connection
1
Using the DB9 cable provided, connect a DB9 port on your computer to a
DB9 port on your UPS. On the computer, install the Tripp Lite power
protection software appropriate to its operating system. A second computer
with a DB9 port may be connected to the second DB9 port if desired.
2
USB Port Connection
Using the USB cable provided, connect a USB port from a computer to a
USB port on your UPS. On the computer, install the Tripp Lite power
protection software appropriate to its operating system. A second USB
computer may be connected to the second USB port if desired.
EPO Port Connection
3
Using the RJ11 cable provided, connect the Emergency Power Off (EPO) port
of your UPS to a user-supplied normally closed or normally open switch
according to the circuit diagram below. The EPO port is not a phone line
surge suppressor; do not connect a phone line to this port.
1
2
3
(UPS will turn off if EPO cord is cut or EPO plug is disconnected)
EPO Circuit Diagrams
5
4-5