JPS57155861A - Line monitoring system - Google Patents

Line monitoring system

Info

Publication number
JPS57155861A
JPS57155861A JP4064381A JP4064381A JPS57155861A JP S57155861 A JPS57155861 A JP S57155861A JP 4064381 A JP4064381 A JP 4064381A JP 4064381 A JP4064381 A JP 4064381A JP S57155861 A JPS57155861 A JP S57155861A
Authority
JP
Japan
Prior art keywords
potential
logical
transmitter
goes
takes place
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
JP4064381A
Other languages
Japanese (ja)
Inventor
Michio Takayama
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.)
NEC Corp
Original Assignee
NEC Corp
Nippon 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 NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP4064381A priority Critical patent/JPS57155861A/en
Publication of JPS57155861A publication Critical patent/JPS57155861A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/24—Testing correct operation
    • H04L1/245—Testing correct operation by using the properties of transmission codes
    • H04L1/247—Testing correct operation by using the properties of transmission codes three-level transmission codes, e.g. ternary

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Dc Digital Transmission (AREA)

Abstract

PURPOSE:To reduce the burden in maintenance of lines, by monitoring the state of line connection with simple constitution, in a reception section of a data communicating system using a bipolar potential. CONSTITUTION:When a normal data signal is transmitted from a transmitter (not shown), since both polarities of potential are produced with a prescribed period, the same polarity of signals are obtained in detector 202 and 203. Thus, the output of an exclusive logical sum circuit 204 goes to logical ''0'' and no alarm generator 205 is operated. If a disconnected wire failure or the like takes place in the transmitter or on a transmission line and no potential is applied to the terminal 201, or if a failure such as a leak takes place anywhere on the transmission line and the potential is minimized in comparison with a normal potential, the output of the circuit 204 goes to logical ''1'' and alarm tone is generated from the alarm generator 205.
JP4064381A 1981-03-21 1981-03-21 Line monitoring system Pending JPS57155861A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4064381A JPS57155861A (en) 1981-03-21 1981-03-21 Line monitoring system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4064381A JPS57155861A (en) 1981-03-21 1981-03-21 Line monitoring system

Publications (1)

Publication Number Publication Date
JPS57155861A true JPS57155861A (en) 1982-09-27

Family

ID=12586233

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4064381A Pending JPS57155861A (en) 1981-03-21 1981-03-21 Line monitoring system

Country Status (1)

Country Link
JP (1) JPS57155861A (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4984510A (en) * 1972-12-19 1974-08-14
JPS5347220A (en) * 1976-10-09 1978-04-27 Toshiba Corp Monitor unit for operation of repeater

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4984510A (en) * 1972-12-19 1974-08-14
JPS5347220A (en) * 1976-10-09 1978-04-27 Toshiba Corp Monitor unit for operation of repeater

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