JPS55100771A - Circuit scan system - Google Patents

Circuit scan system

Info

Publication number
JPS55100771A
JPS55100771A JP788779A JP788779A JPS55100771A JP S55100771 A JPS55100771 A JP S55100771A JP 788779 A JP788779 A JP 788779A JP 788779 A JP788779 A JP 788779A JP S55100771 A JPS55100771 A JP S55100771A
Authority
JP
Japan
Prior art keywords
signal
circuit
subscriber
polarity
line
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.)
Granted
Application number
JP788779A
Other languages
Japanese (ja)
Other versions
JPS6145907B2 (en
Inventor
Yoshihiro Isshiki
Shigeru Arai
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 JP788779A priority Critical patent/JPS55100771A/en
Publication of JPS55100771A publication Critical patent/JPS55100771A/en
Publication of JPS6145907B2 publication Critical patent/JPS6145907B2/ja
Granted legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/50—Circuit switching systems, i.e. systems in which the path is physically permanent during the communication
    • H04L12/52—Circuit switching systems, i.e. systems in which the path is physically permanent during the communication using time division techniques
    • H04L12/525—Circuit switching systems, i.e. systems in which the path is physically permanent during the communication using time division techniques involving a stored program control

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)

Abstract

PURPOSE:To make it possible to measure accurately the guard delay time by detecting the state change of a subscriber's line by combining a received-signal stage with a transmitted-signal stage. CONSTITUTION:In a subscriber's circuit, received signal RD from a subscriber's line after level-converted by receiver 8 is sent to scanning multiplexing part 13 while a signal before passing through driver 9 for level conversion is selected as transmitted signal SD to the subscriber's line by selector circuit 10 and sent out to part 13. The selection of selector circuit 10 is put into effect by selective gate signal 11 from scanning counter part 12. Multiplexing part 13 multiplexes signals RD and SD by circuit number 14 corresponding to circuit coordinate from counter part 12 and then sends them to scanner circuit part 15. By number 14, circuit part 15 extracts corresponding signals RD and SD to detect the signal state. At this time, if signal RD has polarity A and signal SD changes in state from polarity Z to A, a time measurement is immediately started for supervision over the guard delay time. Even if SD has polarity A and RD changes from Z to A to the contrary, the same operation is done.
JP788779A 1979-01-26 1979-01-26 Circuit scan system Granted JPS55100771A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP788779A JPS55100771A (en) 1979-01-26 1979-01-26 Circuit scan system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP788779A JPS55100771A (en) 1979-01-26 1979-01-26 Circuit scan system

Publications (2)

Publication Number Publication Date
JPS55100771A true JPS55100771A (en) 1980-07-31
JPS6145907B2 JPS6145907B2 (en) 1986-10-11

Family

ID=11678095

Family Applications (1)

Application Number Title Priority Date Filing Date
JP788779A Granted JPS55100771A (en) 1979-01-26 1979-01-26 Circuit scan system

Country Status (1)

Country Link
JP (1) JPS55100771A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62200415U (en) * 1986-06-13 1987-12-21

Also Published As

Publication number Publication date
JPS6145907B2 (en) 1986-10-11

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