Camp-on detecting system for automatic telephone exchange
First Claim
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1. In a common control type automatic telephone exchange having a marker, trunk circuits and subscriber'"'"'s line circuits associated therewith, a camp-on detecting system comprising, in combination:
- first means, coupled to a subscriber'"'"'s line circuit, for detecting the existence of a prescribed busy potential on the control line of said subscriber'"'"'s line circuit;
second means, coupled to said first means, and responsive to the existence of a camp-on connection of a trunk circuit with said subscriber'"'"'s line circuit, for changing the potential on the control line of said trunk circuit to a prescribed camp-on potential only when said first means has detected the presence of said prescribed busy potential on the control line of said subscriber'"'"'s line circuit.
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Abstract
A camp-on detecting system for a private automatic branch exchange (PABX) is provided with the camp-on connecting function for connecting queuing or camp-on calls to a busy line circuit. On detecting that the control line of the line circuit is at a busy potential, the potentials on the control lines of all camping-on trunks are changed and the potential changes are detected by the detecting means connected to the line circuit to detect that a camp-on connection has already been made to the line circuit.
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6 Claims
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1. In a common control type automatic telephone exchange having a marker, trunk circuits and subscriber'"'"'s line circuits associated therewith, a camp-on detecting system comprising, in combination:
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first means, coupled to a subscriber'"'"'s line circuit, for detecting the existence of a prescribed busy potential on the control line of said subscriber'"'"'s line circuit; second means, coupled to said first means, and responsive to the existence of a camp-on connection of a trunk circuit with said subscriber'"'"'s line circuit, for changing the potential on the control line of said trunk circuit to a prescribed camp-on potential only when said first means has detected the presence of said prescribed busy potential on the control line of said subscriber'"'"'s line circuit. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification