JPS56141650A - Alarm display release system - Google Patents

Alarm display release system

Info

Publication number
JPS56141650A
JPS56141650A JP4464680A JP4464680A JPS56141650A JP S56141650 A JPS56141650 A JP S56141650A JP 4464680 A JP4464680 A JP 4464680A JP 4464680 A JP4464680 A JP 4464680A JP S56141650 A JPS56141650 A JP S56141650A
Authority
JP
Japan
Prior art keywords
alarm display
signal
circuit
releasing
call signal
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
JP4464680A
Other languages
Japanese (ja)
Inventor
Setsuo Takahashi
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.)
Hitachi Ltd
Original Assignee
Hitachi 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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP4464680A priority Critical patent/JPS56141650A/en
Publication of JPS56141650A publication Critical patent/JPS56141650A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/08—Indicating faults in circuits or apparatus

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Monitoring And Testing Of Exchanges (AREA)

Abstract

PURPOSE:To release an alarm display by providing an alarm display releasing circuit on the telephone switchboard, and by means of a call signal in case when incoming for releasing the alarm display is made to said circuit. CONSTITUTION:When a special number dial related to the alarm display releasing circuit 10 is sent out to the incoming trunk 8 from the telephone set 7, the control unit 1 detects and discrimianates it, selects a call signal trunk 9, and connects it to the alarm display releasing circuit 10 through the network 2. The call signal is rectified by the diode bridge DB of the alarm display releasing circuit 10, and operates the signal detection relay R. It is detected by the current detection element PC that the contact (r) has been closed, an alarm display release signal RST is generated, and it is applied to the reset terminal RES of the flip-flop FF. Accordingly, it is stopped to send out an alarm display signal to the alarm display line 4.
JP4464680A 1980-04-07 1980-04-07 Alarm display release system Pending JPS56141650A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4464680A JPS56141650A (en) 1980-04-07 1980-04-07 Alarm display release system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4464680A JPS56141650A (en) 1980-04-07 1980-04-07 Alarm display release system

Publications (1)

Publication Number Publication Date
JPS56141650A true JPS56141650A (en) 1981-11-05

Family

ID=12697200

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4464680A Pending JPS56141650A (en) 1980-04-07 1980-04-07 Alarm display release system

Country Status (1)

Country Link
JP (1) JPS56141650A (en)

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