Private branch exchange system
First Claim
Patent Images
1. A private branch exchange system comprising:
- an extension terminal; and
an exchange unit which accommodates said extension terminal and an external line and connects said extension terminal and said external line via a main channel or a sub-channel, the extension terminal communicating with the external line before a power failure occurs via the main channel, and the extension terminal communicating with the external line during a power failure via the sub-channel,wherein said extension terminal includes;
connecting means for connecting the exchange via the main channel or the sub-channel,detecting means for detecting use of said sub-channel, andholding means for holding a connection with the external line at restoration from the power failure in a case where use of said sub-channel is detected by said detecting means.
0 Assignments
0 Petitions
Accused Products
Abstract
In a private branch exchange system which includes a private branch exchange accommodating a plurality of line wires and extensions for switching lines between the two, and telephones, which are usable in the event of a power failure, connected to the extensions, the line wires and the power-failure telephones are connected when power feed to the private branch exchange is no longer performed owing to a power failure or the like. When power feed is restored, the call status of the power-failure telephone is monitored and, if it is found that a call is in progress.
-
Citations
25 Claims
-
1. A private branch exchange system comprising:
-
an extension terminal; and an exchange unit which accommodates said extension terminal and an external line and connects said extension terminal and said external line via a main channel or a sub-channel, the extension terminal communicating with the external line before a power failure occurs via the main channel, and the extension terminal communicating with the external line during a power failure via the sub-channel, wherein said extension terminal includes; connecting means for connecting the exchange via the main channel or the sub-channel, detecting means for detecting use of said sub-channel, and holding means for holding a connection with the external line at restoration from the power failure in a case where use of said sub-channel is detected by said detecting means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A private branch exchange system comprising:
-
a channel switch for switchingly connecting before a power failure occurs at least one external line pair and an extension terminal, the extension terminal including communication equipment operable before a power failure occurs which has an extension interface for connecting the channel switch via an extension line on an extension side, wherein communication by said communication equipment is carried out when a power failure occurs, wherein said communication equipment includes; connecting means for connecting the at least one external line wire pair and a line-wire interface of said communication equipment in dependence upon the status of power feed to said exchange; monitoring means for monitoring the status of the communication of said communication equipment which prevails after restoration is made from a power failure; and control means for holding the connection between the at least one external line wire pair and the line-wire interface in dependence upon an output from said monitoring means, wherein if the connection between the at least one external line wire pair and the line-wire interface is held after the restoration is made from the power failure, the communication is established between the at least one external line wire pair and said communication equipment via said connecting means. - View Dependent Claims (12)
-
-
13. A terminal apparatus connectable to an exchange, comprising:
-
connecting means for connecting said terminal apparatus to the exchange via a main line for use before a power failure occurs or a sub-line for power failure; monitoring means for monitoring the status of a call on said sub-line; and maintaining means for maintaining the call during the power failure if the call on said sub-line for power failure is continuing when restoration is made from a power failure. - View Dependent Claims (14, 15, 16, 17)
-
-
18. A switching method of a terminal apparatus including a connector for connecting the terminal apparatus to an exchange via a main line before a power failure occurs and via a sub-line when a power failure occurs, and a monitor for monitoring the status of a call on the sub-line, said method comprising the steps of:
-
connecting the terminal apparatus to the sub-line in dependence upon the status of power feed to the exchange; and performing control in such a manner that, if communication using the sub-line is continuing when restoration is made from a power failure, the communication during the power failure is maintained until the communication ends. - View Dependent Claims (19, 20, 21)
-
-
22. A communication system comprising:
-
exchanging means for exchanging a plurality of external lines and a plurality of extension terminals before a power failure occurs; and first connecting means for connecting one of the plurality of external lines and one of the plurality of extension terminals, bypassing said exchanging means, in an event of a power failure, wherein the one of the plurality of extension terminals includes second connecting means for connecting said exchanging means via a main channel and said first connecting means via a sub-channel, and control means for controlling said second connecting means so as to continue to connect the one of the plurality of external lines and the one of the plurality of extension terminals at restoration from the power failure when the one of the plurality of extension terminals is in communication via the one of the plurality of the external lines. - View Dependent Claims (23)
-
-
24. A communication system comprising an exchanging apparatus and a plurality of extension terminals,
said exchanging apparatus comprising: -
exchanging means for exchanging a plurality of external lines and the plurality of extension terminals before a power failure occurs; and first connecting means for connecting one of the plurality of external lines and one of the plurality of extension terminals via a main pass using said exchanging means or a sub-pass bypassing said exchanging means, one of the plurality of extension terminals comprising; communicating means for communicating via the plurality of external lines, second connecting means for selectively connecting the main pass or the sub-pass to said communicating means, and control means for controlling said second connecting means so as to continue to connect the sub-pass to said communicating means at restoration from the power failure when said communicating means is in communication via the sub-pass. - View Dependent Claims (25)
-
Specification