10 FDU-80 Instruction Manual — P/N 51264:C2 4/24/2019
Section 3: Operation
3.1  Display Patterns
The FDU-80 Annunciator directly displays (mimics) the information on the FACP display with the following exceptions:
Upon Power-up, the FDU-80 may display the following message until a valid message is received from the FACP: 
If an FDU-80 Annunciator fails to receive communications from the panel for a period of over 30 seconds, it will activate its local 
sounder (if so programmed) and display the following message: 
A Communication Fault may be due to one of the following conditions:
• FACP has not been programmed to communicate with the FDU-80.  Refer to the appropriate FACP manual programming section.
• EIA-485 wiring between the 
FDU-80 and FACP has an open.
• Polarity of the EIA-485 wiring between the 
FDU-80 and FACP has been reversed. EIA-485 (-) on the FDU-80 must be connected to EIA-485 
(-) on the FACP and EIA-485 (+) on the 
FDU-80 must be connected to EIA-485 (+) on the FACP.
3.2  Switch Functions
3.2.1  Key-switch
The key-switch is used to enable and disable the operation of the function switches if switch 1 on 
DIP switch SW1 has been placed in the OFF position.
To enable the Acknowledge, Silence, Drill and Reset function switches, insert key into key-switch 
located at the top right corner of the FDU-80. Make certain the key is inserted completely before 
attempting to turn it. Turn the key clockwise until it stops. Leave the key inserted while pressing 
the function switches. When finished with the function switches, turn key-switch counterclock-
wise to disable function switches.
Note that the key-switch should normally be in the disabled position (fully counterclockwise), 
with the key removed and access to the key restricted to authorized personnel only. Do not leave 
the key unattended in the FDU-80.
3.2.2  Acknowledge/Step
When the Acknowledge/Step switch is pressed and released, the FDU-80 sends an Acknowledge command to the control panel. Pressing 
the Acknowledge switch silences the local piezo sounder, the sounders located in all other system annunciators and the sounder located 
on the Fire Alarm Control Panel's main circuit board. Only one press is necessary regardless of the number of new alarms, troubles or 
supervisory signals.
An acknowledge message is also sent to the printer and the history files in the FACP. Multiple active events (alarms, troubles, superviso-
ries) are scrolled on the display at a one second rate, but may be held for sequential display by pressing and holding the Acknowledge 
switch.
When more than one event exists, the first press of the Acknowledge switch silences system piezo sounders. The second press of the 
switch stops the scrolling and holds the event on the display for one minute. Subsequent pressing of the switch 'steps' through each active 
event.
3.2.3  Silence
When the Silence switch is pressed and released, the FDU-80 sends an alarm silence command to the control panel. The Silence switch 
performs the same functions as the Acknowledge switch. In addition, if an alarm exists, it turns off all silenceable NACs and causes the 
FACP Alarm Silenced LED to turn on while the FDU-80 will display a 'silenced' message. It also sends an 'Alarm Silenced' message to 
the printer and the history file within the FACP. A subsequent new alarm will resound the appropriate NACs (Notification Appliance 
Circuits) and local sounders.
3.2.4  Drill: Hold 2 Sec.
When the Drill switch is pressed and held for at least two seconds (time required to prevent accidental activations), the FDU-80 will 
transmit a drill command to the control panel. This command causes the FACP to turn on all NAC outputs and all silenceable circuits (all 
control modules/NACs that are programmed silenceable). In the event that the system was previously silenced, the drill command will 
also turn off the Alarm Silenced LED. The 'Manual Evacuate' message is shown on the FDU-80 display. The same message is sent to the 
FACP display, printer and history files. The Silence switch operates on silenceable NAC outputs only.
INITIALIZING...
PLEASE WAIT
Key-switch (shown in Off position)