Sold As IS. UnKNown history. Removed from service truck inventory

OPERATION The SIEMENS Model MMB-3 board in each MXL System controls operations and monitors input device identity, network communication, and operator commands that are entered through the MKB Annunciator/ Keyboard. The MMB-3 also provides two analog loop driver circuits. Each ALD-2I loop can be used as Class B or Class A and can monitor and control up to 60 intelligent devices as well as programmable device relays. The MMB-3 module can be programmed and upgraded in the field. It is equipped with two programmable Class B (Style Y) or Class A (Style Z) notification appliance circuits. Each circuit can activate up to 1.5 amps of audible or visual notification appliances. The MMB-3 has a user-defined Style 4 or Style 7 MNET communi- cation port. The module also has auxiliary relays for the external monitoring of Common System Alarm, Common System Trouble, and Common Super- visory conditions. The Common Supervisory relay is user programmable. The MMB-3 includes a built-in battery charger and transfer circuit. The charger is microproces- sor controlled and incorporates a brownout circuit that switches the System to standby batteries during the loss or reduction of the primary source AC. The System can display the real time battery voltage, the AC voltage, and the charger current on the MKB display. It also has a 1 amp, 24 VDC output that powers CZM-1/-1B6 modules.