... type security alarm system 2:Monitoring toxic&combustible gas,temperature&pressure signal 3:4-20mA,Expandable channel security alarm systemFeature:1.Standard 4U tray-type ... ) value setting, can separately set pre-alarm, low alarm, high alarm for any address range or any type of detectors4. Detectors sensitivity and zero ... Detector model AT0502AH/L,XP2000/L,XP3000/L 4U tray type security alarm system