Telephone network including common equipment with message information and control information circuits for connecting to stations having multifunction telephones

A telephone network for providing telephone communications between a plurality of sites through a central location, said network comprising:

• A. telephone transmission means for independently interconnecting the central location with at least one site, at least one said transmission means including a first signal path for conveying signals corresponding to acoustic information and a second signal path for conveying data signals,
• B. central switching means, at the central location, connected to each of said first signal paths for selectively interconnecting pairs of said telephone transmission means thereby to transfer acoustic information between interconnected sites,
• C. central telephone control means, at the central location, connected to said central switching means to to said second signal paths for transferring frequency modulated signals representing control data between said control means and each of said second signal paths, and
• D. a multifunction telephone means connected to each of said dual path telephone transmission means at corresponding sites, each said multifunction telephone means including:
• i. acoustic conversion means connected to said first signal path for converting acoustic information between an audible form and an electrical form for transfer between said telephone means and said first signal path,
• ii. at least one first function means for performing a predetermined function in response to control data received from said central telephone means, each said first function means responding to the control data when it is constituted by electrical logic signals,
• iii. at least one second function means for generating electrical logic signals corresponding to control data to be transferred to said central telephone control means, and
• iv. conversion means interconnecting each said function means and said second signal path means including an encoding means for generating frequency modulated signals in response to the electrical logic signals corresponding to the control data for transmission to said central telephone control means and a decoding means for generating signals in logical form in response to frequency modulated signals from said central telephone control means.