COMMUNICATIONEaton 5115 Rack-Mount UPS (500–1500 VA) User's Guide 164201449 Rev B www.eaton.com/powerquality44DB-9 Communication PortTo establish communication between the UPS and a computer, connectyour computer to the UPS communication port using the suppliedcommunication cable.When the communication cable is installed, power managementsoftware can exchange data with the UPS. The software polls the UPSfor detailed information on the status of the power environment. If apower emergency occurs, the software initiates the saving of all dataand an orderly shutdown of the equipment.Figure 23 identifies the cable pins and Table 2 describes the pinfunctions.38 7916245Figure 23. Communication PortTable 2. Communication Port Pin AssignmentPinNumberSignal Name Function Directionfrom the UPS1 Low Batt Low Battery relay contact; 20 mA, 30 Vdccontact ratingOut2 TxD Transmit to external device Out3 RxD Receive from external device In4 DTR PnP (Plug and Play) from external device(tied to Pin 6)In5 GND Signal common (tied to chassis) —6 DSR To external device (tied to Pin 4) Out7 — No Connection —8 AC Fail AC Fail relay contact; 20 mA, 30 Vdccontact ratingOut9 Power Source +V (8 to 24 volts DC power) Out