Terms and Symbols Used 1.4161.4 Terms and Symbols UsedTerminology Line pick-up/seizure/off-hookcall start, line locked, busy. Line hang-up/clearcall end, handset hang-up. DTMFdual tone multi-frequency signalling. PSTNpublic switched telephone network. Outgoing call2N® Helios-telephone connection made, e.g. by a pressing a button. Incoming calltelephone-2N® Helios connection. Programming mode2N® Helios programming mode accessible from by dialling into theintercom only. Code lockmode for entering the password for switch 1 or 2 activation using anumerical keypad. Telephone modeyou can make a call, dial a number and hang up using the numericalkeypad. DTMF transmission during callfor outgoing calls only, numbers are tone-dialled by a numerical keypadbutton. Button substitutionthe numerical keypad can be used instead of a number pre-stored under abutton memory.
