TRUNK LINE INTERFACE DEVICE

PURPOSE:To improve the reliability of the system by reconnecting a digital trunk line interface and an extension terminal interface to a 2nd exchange at a fault of a 1st exchange. CONSTITUTION:When a private branch of exchange 2 is not normally in operation, a ready signal sent from the private bran...

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Bibliographic Details
Main Author AZEYANAGI MIKISUKE
Format Patent
LanguageEnglish
Published 23.05.1991
Subjects
ELECTRIC COMMUNICATION TECHNIQUE
ELECTRICITY
SELECTING
TELEPHONIC COMMUNICATION
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Summary:PURPOSE:To improve the reliability of the system by reconnecting a digital trunk line interface and an extension terminal interface to a 2nd exchange at a fault of a 1st exchange. CONSTITUTION:When a private branch of exchange 2 is not normally in operation, a ready signal sent from the private branch of exchange 2 is interrupted, an adaptor 3 recognizes the occurrence of a fault of the private branch of exchange 2 and outputs a switching signal pattern to a digital trunk line interface 7. A detection circuit 10 identifies the signal to send a switching control signal 11 to relay switches 5, 6, which are changed over and moving contacts 5c, 6c are respectively connected to fixed contacts 5b, 6b. That is, a digital trunk line interface 1 and an extension terminal interface 8 connecting to a terminal equipment 4 are disconnected from the private branch of exchange 2 and connected to an ISDN terminal adaptor 3, which applies exchange connection according to the input from each interface. Thus, the communication is implemented even at a fault of the private branch of exchange 2.
Bibliography:Application Number: JP19890257859