Dell 2700W Video Games User Manual

Additional UPS Features
Table 9. RS-232 Communication Port Pin Assignment
Signal Name Function Direction from the UPS
1 Unused
2 Tx Transmit to external device Out
3 Rx Receive from external device In
4 Unused
5 GND Signal common (tied to chassis)
6 Unused
7 Unused
8 Unused
9 Unused
*Unused pins must be left free on all models.