JPS57162564A - Fault monitor circuit for trunk line circuit of key telephone device - Google Patents

Fault monitor circuit for trunk line circuit of key telephone device

Info

Publication number
JPS57162564A
JPS57162564A JP4699181A JP4699181A JPS57162564A JP S57162564 A JPS57162564 A JP S57162564A JP 4699181 A JP4699181 A JP 4699181A JP 4699181 A JP4699181 A JP 4699181A JP S57162564 A JPS57162564 A JP S57162564A
Authority
JP
Japan
Prior art keywords
trunk line
fault
circuit
telephone device
key telephone
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP4699181A
Other languages
Japanese (ja)
Inventor
Taiji Sato
Yoshiichi Sano
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Toshiba Corp
Tokyo Shibaura Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp, Tokyo Shibaura Electric Co Ltd filed Critical Toshiba Corp
Priority to JP4699181A priority Critical patent/JPS57162564A/en
Publication of JPS57162564A publication Critical patent/JPS57162564A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/002—Arrangements for interconnection not involving centralised switching with subscriber controlled access to a line, i.e. key telephone systems
    • H04M9/005—Arrangements for interconnection not involving centralised switching with subscriber controlled access to a line, i.e. key telephone systems with subscriber controlled access to an exchange line
    • H04M9/006—Exchange line circuits

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Sub-Exchange Stations And Push- Button Telephones (AREA)

Abstract

PURPOSE:To attain the quick recovery of a fault for a key telephone device and to ensure the quick response of a user, by installing a circuit that monitors fault arisen at a trunk line circuit of the telephone device. CONSTITUTION:In case contacts 27 and 28 are kept closed although a trunk line circuit 15 is rung off, the loop of a trunk line 6 is held continuously. Thus one of the light emitting diodes 25 and 26 emits the light, and as a result one of the phototransistors 29 and 30 is turned on. Then the presence or absence of the loop current is informed to a control means 14 from a comparator 34. On the other hand, the means 14 deects the ring-off through a terminal interface circuit, and a fault is decided by the detection of the ring-off and the output signal given from the comparator 34. Thus a fault is displayed. As a result, the user of a key telephone device can know the fault of the trunk line to a quick response for repair, etc.
JP4699181A 1981-03-30 1981-03-30 Fault monitor circuit for trunk line circuit of key telephone device Pending JPS57162564A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4699181A JPS57162564A (en) 1981-03-30 1981-03-30 Fault monitor circuit for trunk line circuit of key telephone device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4699181A JPS57162564A (en) 1981-03-30 1981-03-30 Fault monitor circuit for trunk line circuit of key telephone device

Publications (1)

Publication Number Publication Date
JPS57162564A true JPS57162564A (en) 1982-10-06

Family

ID=12762660

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4699181A Pending JPS57162564A (en) 1981-03-30 1981-03-30 Fault monitor circuit for trunk line circuit of key telephone device

Country Status (1)

Country Link
JP (1) JPS57162564A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63267051A (en) * 1987-04-24 1988-11-04 Sekisui Chem Co Ltd Self fault diagnosing system for telephone set

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63267051A (en) * 1987-04-24 1988-11-04 Sekisui Chem Co Ltd Self fault diagnosing system for telephone set

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