JPS545187A - Trouble diagnosis system of digital signal input circuit - Google Patents

Trouble diagnosis system of digital signal input circuit

Info

Publication number
JPS545187A
JPS545187A JP6986777A JP6986777A JPS545187A JP S545187 A JPS545187 A JP S545187A JP 6986777 A JP6986777 A JP 6986777A JP 6986777 A JP6986777 A JP 6986777A JP S545187 A JPS545187 A JP S545187A
Authority
JP
Japan
Prior art keywords
digital signal
signal input
input circuit
diagnosis system
trouble diagnosis
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
JP6986777A
Other languages
Japanese (ja)
Inventor
Takashi Uchida
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 JP6986777A priority Critical patent/JPS545187A/en
Publication of JPS545187A publication Critical patent/JPS545187A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/20—Repeater circuits; Relay circuits
    • H04L25/26—Circuits with optical sensing means, i.e. using opto-couplers for isolation

Abstract

PURPOSE:To recognise the safety of photocouplers, by means of detecting the action by giving periodically and artificially an ON/OFF signal to the photocouplers used for indicating input part of the branch office of a tele monitoring device.
JP6986777A 1977-06-15 1977-06-15 Trouble diagnosis system of digital signal input circuit Pending JPS545187A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6986777A JPS545187A (en) 1977-06-15 1977-06-15 Trouble diagnosis system of digital signal input circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6986777A JPS545187A (en) 1977-06-15 1977-06-15 Trouble diagnosis system of digital signal input circuit

Publications (1)

Publication Number Publication Date
JPS545187A true JPS545187A (en) 1979-01-16

Family

ID=13415163

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6986777A Pending JPS545187A (en) 1977-06-15 1977-06-15 Trouble diagnosis system of digital signal input circuit

Country Status (1)

Country Link
JP (1) JPS545187A (en)

Similar Documents

Publication Publication Date Title
JPS54947A (en) Failure detection system for digital output circuit
JPS545187A (en) Trouble diagnosis system of digital signal input circuit
JPS53132934A (en) Detector for abnormal state of data transmitter
JPS54812A (en) Repeating system
JPS5395480A (en) Accident information device
JPS5422103A (en) Transmisson-reception switch control system for semidouble communication
JPS5431884A (en) Abnormality detecting apparatus in transmission system
JPS53120309A (en) Terminal test system
JPS52152051A (en) Elevator signal transmitting device
JPS5398704A (en) Optical multiplex transmission system
JPS53131715A (en) Circuit selection system
JPS53124005A (en) Monitor system for subscriber line
JPS5390707A (en) Detecting system for circuit fault
JPS51138107A (en) Signal detection output system
JPS54918A (en) Facsimile transmission system
JPS53131706A (en) Automatic telephone exchange system
JPS52149005A (en) S/n value signal concentrated monitoring system
JPS5617537A (en) Information transmitting system using optical data bus line
JPS52149011A (en) Pilot circuit block signal monitor system
JPS52109307A (en) Information transmission device
JPS52109308A (en) Information transmission device
JPS52109309A (en) Information transmission device
JPS52121749A (en) Protective relay device
JPS53105919A (en) Ring-down control system
JPS544007A (en) Identifying system of two terminals and two common subscribers