JPS55124351A - Signal transmission system - Google Patents

Signal transmission system

Info

Publication number
JPS55124351A
JPS55124351A JP3102979A JP3102979A JPS55124351A JP S55124351 A JPS55124351 A JP S55124351A JP 3102979 A JP3102979 A JP 3102979A JP 3102979 A JP3102979 A JP 3102979A JP S55124351 A JPS55124351 A JP S55124351A
Authority
JP
Japan
Prior art keywords
signal
circuit
detected
telephone
call
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
JP3102979A
Other languages
Japanese (ja)
Other versions
JPS588183B2 (en
Inventor
Kyoichi Nakakawara
Fukue Ogawa
Hiroshi Sekiguchi
Masanori Nakazawa
Yoshimi Sato
Kazuhiko Shirai
Original Assignee
Toshiba Corp
Nippon Telegr & Teleph Corp <Ntt>
Nec Corp
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 Toshiba Corp, Nippon Telegr & Teleph Corp <Ntt>, Nec Corp filed Critical Toshiba Corp
Priority to JP3102979A priority Critical patent/JPS588183B2/ja
Publication of JPS55124351A publication Critical patent/JPS55124351A/en
Publication of JPS588183B2 publication Critical patent/JPS588183B2/ja
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04MTELEPHONIC COMMUNICATION
    • H04M11/00Telephonic communication systems specially adapted for combination with other electrical systems
    • H04M11/06Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors

Abstract

PURPOSE:To secure the call-priority state for the subscriber's telephone even under the data communication, by transmitting the AC reply signal from the terminal unit when the specified terminal call signal is detected by the network control unit. CONSTITUTION:Exchange 1 catches telephone circuit 2 and then inverts the polarity of circuit 2 to secure the piling of the specified terminal call signal. Switch circuit 41 is closed by the polarity inversion of circuit 2, and the call signal is detected by signal detection circuit 42a to close switch circuit 43a. Thus the connection line is closed between circuit 2 and terminal unit 5a. As a result, unit 5a is started to transmit AC replay signal Sa. Then telephone 3 is hooked off to be detected by off-hook detection circuit 44, and thus circuit 41 is turned off to cut off signal Sa. As a result, exchange 1 detects the cut-off of signal Sa to give the priority to the call of telephone 3. At the same time, signal Sa is detected at the center unit to complete the data communication.
JP3102979A 1979-03-19 1979-03-19 Expired JPS588183B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3102979A JPS588183B2 (en) 1979-03-19 1979-03-19

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3102979A JPS588183B2 (en) 1979-03-19 1979-03-19

Publications (2)

Publication Number Publication Date
JPS55124351A true JPS55124351A (en) 1980-09-25
JPS588183B2 JPS588183B2 (en) 1983-02-15

Family

ID=12320079

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3102979A Expired JPS588183B2 (en) 1979-03-19 1979-03-19

Country Status (1)

Country Link
JP (1) JPS588183B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59132274A (en) * 1983-01-19 1984-07-30 Oki Electric Ind Co Ltd Calling system of subscriber
JPS61200790A (en) * 1985-03-01 1986-09-05 Sharp Corp Image information transmission system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59132274A (en) * 1983-01-19 1984-07-30 Oki Electric Ind Co Ltd Calling system of subscriber
JPS61200790A (en) * 1985-03-01 1986-09-05 Sharp Corp Image information transmission system

Also Published As

Publication number Publication date
JPS588183B2 (en) 1983-02-15

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