... ADPCMAudio Input1/2/4 channel, RCA port, liner input, Impedance:1KOhmsAudio Output1channel,RCA port, linear outputAudio talk-back input1 channel , ... . position adjustableCommunication Interface1 10M/100M self-adapting Ethernet port, RS485 port, RS232 portBuilt-in some high-speed protocols and ... SD2.0 standard. (Max 32G SD card), Support FTP server.Alarm Input 4 channel on/off input, supporting NO ( ...