Alarm box 1,RS485 and RS232 interface 2,Compatible with many protocolas:Unsight,Hikvision,Myteh etc. 3, ... , DVR software, embedded DVR or matrix engine through RS485 or RS232 bus, then according to the customer's parameter setting active ... recording,alarm remote transmission etc. Multi-alarm mainframe or alarm card do cascade with alarm mainframe through RS485 bus, to increase ...