Multi-line telephone system
First Claim
1. A multi-line telephone system comprising:
- a plurality of telephone station sets operably connected together;
at least one of said station sets being adapted to interface with telephone CO lines;
at least one of said station sets being adapted to interface with a common power source;
a bus means operably connecting said station sets together in bussed loop fashion;
said bus means including at least one status signal conductor for providing CO line status information to said station sets;
each said station set having drive circuit means for impressing variable value CO line status signals on said one status signal conductor in accordance with the line status imparted by the respective said station set, and detector circuit means for detecting the varying values of such a line status signal;
reference voltage generating means located in each said station set and independently operable from such a common power source to generate in each said station set reference voltages for comparison with such a line status signal by said detector circuit means to determine CO line status; and
each said station set further including indicator means which are operable in response to the line status signal detected by the said detector circuit means of the respective said station sets to inform users of said respective station sets of CO line status.
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Accused Products
Abstract
A multi-line, multi-instrument telephone system having no key service unit and wherein decentralized or local indicator lamp and paging circuit management functions are provided which are operative independently in each station set to operate and control the indicator lamps and paging circuits through selective local generation and alteration of control signals and comparison of the control signals with locally generated reference voltage signals to provide basis for decisions on required visual and audible indicator status. The system is connected in loop fashion with each instrument being connected across a common, multiconductor buss wherein a single conductor supports lamp supervision signaling for the multiple lines and another single conductor supports intercom status signaling, intercom audio, paging audio, and the ring signal.
92 Citations
21 Claims
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1. A multi-line telephone system comprising:
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a plurality of telephone station sets operably connected together; at least one of said station sets being adapted to interface with telephone CO lines; at least one of said station sets being adapted to interface with a common power source; a bus means operably connecting said station sets together in bussed loop fashion; said bus means including at least one status signal conductor for providing CO line status information to said station sets; each said station set having drive circuit means for impressing variable value CO line status signals on said one status signal conductor in accordance with the line status imparted by the respective said station set, and detector circuit means for detecting the varying values of such a line status signal; reference voltage generating means located in each said station set and independently operable from such a common power source to generate in each said station set reference voltages for comparison with such a line status signal by said detector circuit means to determine CO line status; and each said station set further including indicator means which are operable in response to the line status signal detected by the said detector circuit means of the respective said station sets to inform users of said respective station sets of CO line status. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. In a communications apparatus wherein a plurality of telephone station sets are operably interconnected to provide a multi-line, multi-station telephone system with at least one station set adapted to interface with telephone CO lines to provide multi-line capability for all of the station sets and with at least one station set being adapted to interface with a power source, and wherein each respective station set includes intercom capability for intercom communication with any other of the station sets and further includes system wide line status supervision and indication, the improvement comprising:
said station sets being operably interconnected by a cable bus having no more than eight electrical conductors. - View Dependent Claims (21)
Specification