108Name FunctionMIC OUT Audio output port Audio output port. It is to output the analog audio signalto the devices such as the sound box. Bidirectional talk output. Audio output on 1-window video monitor. Audio output on 1-window video playback.1～8 Alarm input port1～8 There are two groups. The first group is from port1 to port 4; the second group is from port 5 to port8. They are to receive the signal from the externalalarm source. There are two types; NO (normalopen)/NC (normal close). When your alarm input device is using externalpower, please make sure the device and the NVRhave the same ground.GND Alarm input ground port.NO1～NO3Alarm output port1～3 3 groups of alarm output ports. (Group 1：portNO1 ～ C1,Group 2:port NO2 ～ C2,Group 3:portNO3 ～ C3 ） ).Output alarm signal to the alarmdevice. Please make sure there is power to theexternal alarm device. NO：Normal open alarm output port. C：Alarm output public end.C1～C3A RS-485communicationportRS485_A port. It is the cable A. You can connect to thecontrol devices such as speed dome PTZ.B RS485_B.It is the cable B. You can connect to thecontrol devices such as speed dome PTZ.Power input port Input DC 12V/5A.Powerswitch / Power on/off button.2.2.17 NVR72-8P SeriesThe NVR72-8P series rear panel is shown as below. See Figure 2-58.Figure 2-58Please refer to the following sheet for detailed information.Name FunctionUSB2.0 port USB2.0 port. Connect to mouse, USB storagedevice, USB burner and etc.
