JPS57148433A - Monitoring circuit for optical relay - Google Patents

Monitoring circuit for optical relay

Info

Publication number
JPS57148433A
JPS57148433A JP56033082A JP3308281A JPS57148433A JP S57148433 A JPS57148433 A JP S57148433A JP 56033082 A JP56033082 A JP 56033082A JP 3308281 A JP3308281 A JP 3308281A JP S57148433 A JPS57148433 A JP S57148433A
Authority
JP
Japan
Prior art keywords
circuit
output
relay
comparator
gate
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
JP56033082A
Other languages
Japanese (ja)
Inventor
Haruo Fujiwara
Masaaki Takahashi
Mitsuhiro Motegi
Hiroshi Nishimoto
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.)
Fujitsu Ltd
Original Assignee
Fujitsu 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 Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP56033082A priority Critical patent/JPS57148433A/en
Publication of JPS57148433A publication Critical patent/JPS57148433A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B17/00—Monitoring; Testing
    • H04B17/40—Monitoring; Testing of relay systems
    • H04B17/401—Monitoring; Testing of relay systems with selective localization
    • H04B17/402—Monitoring; Testing of relay systems with selective localization using different frequencies
    • H04B17/404—Monitoring; Testing of relay systems with selective localization using different frequencies selected by local filters

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Monitoring And Testing Of Transmission In General (AREA)
  • Optical Communication System (AREA)

Abstract

PURPOSE:To achieve normal monitoring without sending an error signal by utilizing a BPF for selecting a relay in common by a relay for both up and down circuits, and controlling the gate of a transmission line by discriminating the presence of the output of the BPF. CONSTITUTION:If a transmission system has a fault at an optical relay, a transmitting terminal station sends detection signals having different frequencies to respective relays. At the relay, the detection signal having the assigned frequency is selected by a BPF17 after passing through an NRZ/RZ converting circuit 13a, and a comparator 18 discriminates the presence of its output. The output of the comparator 18 is applied to an AND circuit 19 to open a gate 15b for return from the circuit 13a to an OR gate 15b, and the output of the comparator 18 turns off AND gates 14a and 14b through an inverter 21, cutting off an up and a down transmission line. Consequently, the output of the NRZ/NZ converting circuit 13b is prevented from being inputted to the LD driving circuit 16b of the same circuit, so that even if an input signal break detecting circuit malfunctions, normal monitoring is carried out.
JP56033082A 1981-03-10 1981-03-10 Monitoring circuit for optical relay Pending JPS57148433A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56033082A JPS57148433A (en) 1981-03-10 1981-03-10 Monitoring circuit for optical relay

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56033082A JPS57148433A (en) 1981-03-10 1981-03-10 Monitoring circuit for optical relay

Publications (1)

Publication Number Publication Date
JPS57148433A true JPS57148433A (en) 1982-09-13

Family

ID=12376768

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56033082A Pending JPS57148433A (en) 1981-03-10 1981-03-10 Monitoring circuit for optical relay

Country Status (1)

Country Link
JP (1) JPS57148433A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5130837A (en) * 1989-07-27 1992-07-14 Fujitsu Limited Optical repeater haivng means for preventing malfunction due to the presence of noise

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5130837A (en) * 1989-07-27 1992-07-14 Fujitsu Limited Optical repeater haivng means for preventing malfunction due to the presence of noise

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