Central analog phone lines from 2 to 6 urban input internal users with caller identification. Fax switch, automatic recognizer incoming faxes, answering courtesy customizable DISA voice, programming via PC program SL-set supplied. Leads to diffusion plant messages (paging), door entry alarms dialer entrance doors, external music on hold, analog modem port, RS232 port for PC or printer, connection for connecting buzzer, lamps muduli field associated with any internal direct connection to emergency batteries in the absence of mains. Shared phone book for 89 numbers.