The MS-5210UD is a combination control panel and digital communicator all on one circuit board. It is a 10-zone panel, which uses conventional input devices. The panel accepts waterflow devices, two-wire smoke detectors, four-wire smoke detectors, pull stations and other normally-open contact devices. Outputs include two Notification Appliance Circuits (NACs) expandable to four, two programmable Form-A relays (option module with two Form-C relays can be added), EIA-485 port to interface with remote annunciators and optional remote relay modules plus a printer port. The integral communicator transmits system status (alarms, troubles, AC loss, others) to UL-listed central stations via the public switched telephone network. The control panel has a built-in programmer. It also supervises all wiring, AC voltage, telephone line input voltage/current and battery level.