... running of system, and support video, data business, AV synchronization and two way voice communications;l2cards 3G ... surveillance, order triggerRecorders inquiryTime retrieval, fact retrieval, channel retrievalWay of BackupsInternet backup, USB backupVideo input4 route BNC ... /sec(adjustable)NTSC:30frames/sec (adjustable)record storageHDD,SD Card, networkLocal Replay1 route,4 route replayAlarm ...