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JPS57210790A - Telephone exchanger - Google Patents

Telephone exchanger

Info

Publication number
JPS57210790A
JPS57210790A JP9509581A JP9509581A JPS57210790A JP S57210790 A JPS57210790 A JP S57210790A JP 9509581 A JP9509581 A JP 9509581A JP 9509581 A JP9509581 A JP 9509581A JP S57210790 A JPS57210790 A JP S57210790A
Authority
JP
Japan
Prior art keywords
relay
subscriber
terminal
closed
circuit
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
JP9509581A
Other languages
Japanese (ja)
Inventor
Tsutomu Kunida
Junya Ishizaki
Taro Matsui
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 JP9509581A priority Critical patent/JPS57210790A/en
Publication of JPS57210790A publication Critical patent/JPS57210790A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Exchange Systems With Centralized Control (AREA)
  • Interface Circuits In Exchanges (AREA)

Abstract

PURPOSE:To avoid complicated circuit and to make maintenance and inspection easy, by using the same circuit for a subscriber and incoming trunk circuit. CONSTITUTION:When a subscriber 1 hooks off, a current flows to the 3rd relay coil 70 and contacts 72 and 73 of the 3rd relay are closed. Terminals 40 and 41 go to 0V and this is detected with a CPU12. The CPU12 connects the subscriber 1 and an outgoing register 9 with a crossbar switch 7. After the connection, a terminal 27 goes to 0V. Thus, the 2nd relay 60 and the 4th relay 80 are operated, but since a contact 64 and the like are closed, a signal from a terminal 39 does not enter the subscriber 1. If a called party is busy and the line can not be connected, the terminal 27 is resotred to open state from 0V with the outgoing register 9. Then, the 2nd relay 60 is restored but the 4th relay is not restored but remains to be kept closed. This shows the lockout state and in this state, the 3rd relay 70 is inoperative. The operation for an incoming trunk 3 is almost the same.
JP9509581A 1981-06-19 1981-06-19 Telephone exchanger Pending JPS57210790A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9509581A JPS57210790A (en) 1981-06-19 1981-06-19 Telephone exchanger

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9509581A JPS57210790A (en) 1981-06-19 1981-06-19 Telephone exchanger

Publications (1)

Publication Number Publication Date
JPS57210790A true JPS57210790A (en) 1982-12-24

Family

ID=14128332

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9509581A Pending JPS57210790A (en) 1981-06-19 1981-06-19 Telephone exchanger

Country Status (1)

Country Link
JP (1) JPS57210790A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03131194A (en) * 1989-10-17 1991-06-04 Fujitsu Ltd Integrated interface circuit

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03131194A (en) * 1989-10-17 1991-06-04 Fujitsu Ltd Integrated interface circuit

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