Ericsson DIALOG 4220 - Manual (Page 9)

9 Dialog 4220 Lite/Dialog 4222 Office
Description
Lamp indications
Ô
Extinguished lamp The function is not active.
Х Ф
Steady light
The function is active or multiple
represented line is busy.
Ц Ф
Slowly flashing lamp The line (or function) is put on hold.
Ц Ф
Rapidly flashing lamp An incoming call.
Х Ф
Light with short breaks Ongoing call.