... method, Optimal audio/ video synchronization. Motion Detection,Alarm output,imput, Timing recording, Immediate manual video recording, Alarm video recording, Video recording document inquiry ... ,Audio1channel audio input 1channel video outputCommunication InterfaceRJ45 10M/100M Ethernet Alarm/RS485 USB2.0OtherOperating temperatureIndoor(-45°C~+55°C)Ambient humidity ...