Settings > Call Signalling > Flashing Display Backlight for Call Signalling

Flashing Display Backlight for Call Signalling
If you don't want your environment to be disturbed by the ringer on the telephone, you can signal calls instead by having the display backlight flash (in addition to the other visual signals). Depending on the brightness in the room, this can be a highly noticeable visual signal.
 
 
Warning: Certain blinking frequencies can possibly trigger epileptic seizures. Those suffering from or in danger of epileptic seizures should therefore avoid using this function.
 
 
Proceed as follows:
Using COMfortel Set (page Settings/functions > Signalling/ringer, check box Call signal/light)
Using the telephone (menu functions > call signal/light)

COMfortel 1200 - Firmware V2.2 - COMfortel Set V3.16 - Advanced Information V07 02/2019