Public telephone set
First Claim
1. A public telephone set having an alarm information transmission function for performing a self-diagnosis for predetermined test positions upon detection of a ringing signal from an office line and automatically forming a DC loop, for transmitting a self-diagnostic result in a predetermined form of a signal, and for releasing the DC loop, comprising:
- communication enabling means for enabling incoming communication upon formation of the DC loop based on the incoming call;
signal detecting means for detecting a protocol signal from a maintenance center or a service center via the office line;
timer means started upon formation of the DC loop; and
control means for sending out alarm information to said maintenance center or said service center via the office line when said signal detecting means generates a detection output during an operation of said timer means.
1 Assignment
0 Petitions
Accused Products
Abstract
A public telephone set includes a communication enabling unit, a signal detector, a timer, and a CPU. The communication enabling unit enables incoming communication upon formation of a DC loop based on an incoming call. The signal detector detects a protocol signal from a maintenance center or a service center via the office line. The timer is started upon formation of the DC loop. The CPU instructs to send out alarm information to the maintenance or the service center via the office line when the signal detector generates a detection output during an operation of the timer.
5 Citations
8 Claims
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1. A public telephone set having an alarm information transmission function for performing a self-diagnosis for predetermined test positions upon detection of a ringing signal from an office line and automatically forming a DC loop, for transmitting a self-diagnostic result in a predetermined form of a signal, and for releasing the DC loop, comprising:
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communication enabling means for enabling incoming communication upon formation of the DC loop based on the incoming call; signal detecting means for detecting a protocol signal from a maintenance center or a service center via the office line; timer means started upon formation of the DC loop; and control means for sending out alarm information to said maintenance center or said service center via the office line when said signal detecting means generates a detection output during an operation of said timer means. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A public telephone set having an alarm information transmission function for performing a self-diagnosis for predetermined test positions upon detection of a ringing signal from an office line and automatically forming a DC loop, for transmitting a self-diagnostic result in a predetermined form of a signal, and for releasing the DC loop, comprising:
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hook state determining means for determining a hook state upon formation of the DC loop in response to an incoming call; and control means for allowing incoming communication when said hook state determining means determines an off-hook state and for sending out the alarm information to the office line when said hook state determining means determines an on-hook state.
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Specification