JPS57143950A - Monitoring circuit for auxiliary circuit - Google Patents

Monitoring circuit for auxiliary circuit

Info

Publication number
JPS57143950A
JPS57143950A JP56030271A JP3027181A JPS57143950A JP S57143950 A JPS57143950 A JP S57143950A JP 56030271 A JP56030271 A JP 56030271A JP 3027181 A JP3027181 A JP 3027181A JP S57143950 A JPS57143950 A JP S57143950A
Authority
JP
Japan
Prior art keywords
signal
circuit
transmission
analog
digital
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
JP56030271A
Other languages
Japanese (ja)
Inventor
Masahiro Nakajima
Hiromi Hashimoto
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 JP56030271A priority Critical patent/JPS57143950A/en
Publication of JPS57143950A publication Critical patent/JPS57143950A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/04—Control of transmission; Equalising
    • H04B3/10—Control of transmission; Equalising by pilot signal

Landscapes

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

Abstract

PURPOSE:To monitor a fault on an A/D transmission line continuously by signal processing at a reception side without transmitting and receiving a control signal between a transmission and a reception side, by detecting the switching control period of the A/D signal of the transmission side by the state change of an output signal of detection of a pilot signal. CONSTITUTION:An analog signal 1 and a digital signal 2 are generated by analog and digital pilot signal generating circuits 106 and 107, and are alternated at a constant period T in an A/D converting circuit 104 by a control signal 3 from a switching control circuit 105 to be transmitted from a transmitting circuit 103. This signal is received by a receiving circuit 108, and is branched to pilot detecting circuits 111 and 112 for analog and digital transmission through a demodulating circuit 109 for analog transmission and a demodulating circuit 110 for digital transmission. Then, state change signals 5 and 6 from those circuits 111 and 112 are applied to a phase comparing circuit 116 and the 1st and 2nd change point detecting circuits 113 to detect a switching control period, thereby monitoring a fault on an A/D transmission line continuously.
JP56030271A 1981-03-03 1981-03-03 Monitoring circuit for auxiliary circuit Pending JPS57143950A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56030271A JPS57143950A (en) 1981-03-03 1981-03-03 Monitoring circuit for auxiliary circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56030271A JPS57143950A (en) 1981-03-03 1981-03-03 Monitoring circuit for auxiliary circuit

Publications (1)

Publication Number Publication Date
JPS57143950A true JPS57143950A (en) 1982-09-06

Family

ID=12299032

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56030271A Pending JPS57143950A (en) 1981-03-03 1981-03-03 Monitoring circuit for auxiliary circuit

Country Status (1)

Country Link
JP (1) JPS57143950A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002013379A3 (en) * 2000-08-04 2003-03-06 Scientific Atlanta Amplifier with a universal automatic gain control circuit

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002013379A3 (en) * 2000-08-04 2003-03-06 Scientific Atlanta Amplifier with a universal automatic gain control circuit
US6995806B1 (en) 2000-08-04 2006-02-07 Scientific-Atlanta, Inc. Amplifier with a universal automatic gain control circuit

Similar Documents

Publication Publication Date Title
JPS5784377A (en) Device for detecting obstacle
JPS56149148A (en) Signal transmission system
JPS57143950A (en) Monitoring circuit for auxiliary circuit
JPS57173245A (en) Data transmission system
JPS5639655A (en) N-to-one stand-by switching system of radio digital transmission
JPS5555646A (en) Failure detection system for remote monitor system
JPS57121344A (en) Transmission system alarm indication signal
JPS54151875A (en) Disconnection detector for transmission circuits
JPS6429997A (en) Environmental abnormality alarming facility
JPS56156020A (en) Arithmetic processor
JPH05189687A (en) Transmitter with redundant function
JPS5473595A (en) Abnormal state detecting system
JPS57162546A (en) Alarm detecting system of time-division multidirection communication network
JPS5732145A (en) Pilot control system
JPS5444170A (en) Digital controller
JPS6413824A (en) Signal detection circuit
JPS567063A (en) Detecting method for signal line short-circuited spot
JPS53133470A (en) Convergence value detecting system
JPS55132143A (en) Diversity system
JPS63164717A (en) Antenna system
JPS54129812A (en) Line monitor system
JPS57123793A (en) Two-wire signal transmission system
JPS52140840A (en) Transmission protection relay system
JPS551773A (en) Channel selector for automatic sweep receiver
JPS54157404A (en) Concentrator