... snapshot, record, replaySupport 1-2pcs SATA HDD (Optional), USB, SD card interfaceSupport RS232 and RS485 (PTZ) interface ModelAST-8304F- ... p, 75Ω)Video Loop outBNC(1.0Vp-p,75Ω)Audio Input1 channel MIC input, 4 channel BNC inputAudio output1 ... External output activation; Local recordingE-MapBMP E-MapCommunication portUSB, SD card, 1 RS232, 1 RS485 interfaceSDKSDK available for application ...