Philips D721 - Manual (Page 68)

5 Emergency operation
5.1 Emergency operation switch
Emergency operation commences in the event of a power failure.
Connected to an NTBA in the emergency mode, the S0 bus can only power
a terminal that is capable of emergency operation. If you are operating
several terminals on the bus, the emergency mode must only be activated
on one of the terminals.
Switching to the emergency mode
Remove all plugs from the terminal.
Take a screw driver and turn the switch to
position 1.
Mark this terminal as the emergency terminal
Note:
When delivered, your telephone is not set to
emergency operation.
5.2 In an emergency
If the power supply on your NTBA should fail, only the terminal set to the
emergency mode will operate on the bus. All calls for the bus will be
signalled at this one telephone. When you are making telephone calls, the
emergency mode is indicated by a "!" between the date and the time on
the display.
SmartLine D721:
The analog port is not available during emergency operation.
67
1
2
1
2
Switch setting
1 Emergency operation possible
2 Emergency operation not possible