JPS5792964A - Network control device - Google Patents

Network control device

Info

Publication number
JPS5792964A
JPS5792964A JP16786180A JP16786180A JPS5792964A JP S5792964 A JPS5792964 A JP S5792964A JP 16786180 A JP16786180 A JP 16786180A JP 16786180 A JP16786180 A JP 16786180A JP S5792964 A JPS5792964 A JP S5792964A
Authority
JP
Japan
Prior art keywords
relay
telephone set
lines
telephone
photocoupler
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
JP16786180A
Other languages
Japanese (ja)
Inventor
Toshio Watanabe
Iwao Shimizu
Makoto Suzuki
Toshihiko Nishimura
Shigeru Okamura
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.)
JAPANESE NATIONAL RAILWAYS<JNR>
Japan National Railways
Mitsubishi Electric Corp
Nippon Kokuyu Tetsudo
Original Assignee
JAPANESE NATIONAL RAILWAYS<JNR>
Japan National Railways
Mitsubishi Electric Corp
Nippon Kokuyu Tetsudo
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 JAPANESE NATIONAL RAILWAYS<JNR>, Japan National Railways, Mitsubishi Electric Corp, Nippon Kokuyu Tetsudo filed Critical JAPANESE NATIONAL RAILWAYS<JNR>
Priority to JP16786180A priority Critical patent/JPS5792964A/en
Publication of JPS5792964A publication Critical patent/JPS5792964A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
    • H04M11/06—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors

Landscapes

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

Abstract

PURPOSE:To transmit a busy signal to an additional telephone to indicate the busy state of a line audibly if the line is used by another devic, by discriminating automatically off-hook and on-hook at the call time by a DC power source and a current detecting circuit in the device. CONSTITUTION:Telephone lines L1 and L2 are connected to a telephone set 8 through a CML relay contact 4 and the break contact of an A relay contact 14; and when the relay A is operated, the voltage of a DC power source 16 is applied to the telephone set 8. When the telephone set is hooked off, a DC loop is formed, and a photocoupler 20 becomes conductive, and an on-hook signal line 23 is set to L, and the relay A is released, and thus, the telephone set 8 is connected to lines, and the calling subscriber is connected to the called subscriber by dialing. When the called subscriber answers, the voltage polarity of lines is inverted, and a photocoupler 21 becomes conductive, and the relay A is operated when the photocoupler 21 becomes non-conductive by the end of power supply. If the telephone set 8 is hooked off when lines are used by a data device and etc, a busy signal is inputted from a busy signal generating circuit 18 to the telephone set because a relay B is operated.
JP16786180A 1980-11-28 1980-11-28 Network control device Pending JPS5792964A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16786180A JPS5792964A (en) 1980-11-28 1980-11-28 Network control device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16786180A JPS5792964A (en) 1980-11-28 1980-11-28 Network control device

Publications (1)

Publication Number Publication Date
JPS5792964A true JPS5792964A (en) 1982-06-09

Family

ID=15857440

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16786180A Pending JPS5792964A (en) 1980-11-28 1980-11-28 Network control device

Country Status (1)

Country Link
JP (1) JPS5792964A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5748859A (en) * 1980-09-08 1982-03-20 Toshiba Corp Network controller

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5748859A (en) * 1980-09-08 1982-03-20 Toshiba Corp Network controller

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