COMMUNICATIONEATON Powerware® 9125 Two-in-One UPS (5000/6000 VA) User’s Guide S 164201513 Rev Bwww.powerware.com38DB-9 Communication PortTo establish communication between the UPS and a computer, connectyour computer to the UPS communication port using the suppliedcommunication cable (see Figure 18).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.The cable pins are identified in Figure 19 and the pin functions aredescribed in Table 3.387 9162 4 5Figure 19. Communication PortTable 3. Communication Port Pin AssignmentPin Number Signal Name Function Direction from the UPS1 Low Batt Low Battery relay contact; 20 mA, 30 Vdc contact rating Out2 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 Vdc contact rating Out9 Power Source +V (8 to 24 volts DC power) Out