Alarm I/O: Connections: Alarm input could connect to such "fire alarm", "door open alarm" ...etc. Alarm output could connect to "Speaker", "alarm LED" ...etc. Description for each contact: NA, NA, CO1, NO1, NC1 Reply: NA = no used, it is empty pin/socket. When the DSLAM alarm = 0, CO1 and NC1 is short. When the DSLAM alarm = 1, CO1 and NO1 is short. Circuits: By default configuration, 4 x alarm input are opened, and CO1 and NC1 are short with alarm output. Voltages: The maximum current and voltage for alarm module of DAS3series_RevC is restricted to 2A 24VDC or 1A 120VAC (resistive load).