JPS57143970A - Self-testing system for multifrequency signal receiver - Google Patents

Self-testing system for multifrequency signal receiver

Info

Publication number
JPS57143970A
JPS57143970A JP56029714A JP2971481A JPS57143970A JP S57143970 A JPS57143970 A JP S57143970A JP 56029714 A JP56029714 A JP 56029714A JP 2971481 A JP2971481 A JP 2971481A JP S57143970 A JPS57143970 A JP S57143970A
Authority
JP
Japan
Prior art keywords
circuit
output
fault
circuits
discrete fourier
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
JP56029714A
Other languages
Japanese (ja)
Other versions
JPH0343819B2 (en
Inventor
Akira Fukui
Shiro Kikuchi
Masaki Ehata
Makoto Mori
Takaaki Osaki
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
Hitachi Ltd
NEC Corp
Nippon Telegraph and Telephone Corp
Oki Electric Industry Co Ltd
Original Assignee
Fujitsu Ltd
Hitachi Ltd
NEC Corp
Nippon Telegraph and Telephone Corp
Oki Electric Industry Co Ltd
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 Fujitsu Ltd, Hitachi Ltd, NEC Corp, Nippon Telegraph and Telephone Corp, Oki Electric Industry Co Ltd, Nippon Electric Co Ltd filed Critical Fujitsu Ltd
Priority to JP56029714A priority Critical patent/JPS57143970A/en
Publication of JPS57143970A publication Critical patent/JPS57143970A/en
Publication of JPH0343819B2 publication Critical patent/JPH0343819B2/ja
Granted legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q1/00—Details of selecting apparatus or arrangements
    • H04Q1/18—Electrical details
    • H04Q1/30—Signalling arrangements; Manipulation of signalling currents
    • H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
    • H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
    • H04Q1/45—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling
    • H04Q1/457—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling with conversion of multifrequency signals into digital signals
    • H04Q1/4575—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling with conversion of multifrequency signals into digital signals which are transmitted in digital form

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
  • Monitoring And Testing Of Exchanges (AREA)

Abstract

PURPOSE:To test both circuits, finding a real number part, and finding an imaginary number part, in a discrete Fourier transformation circuit, by finding the absolute value of a discrete Fourier transformation output and comparing the value with a threshold value. CONSTITUTION:An input singal from an input terminal 1 is inputted to a circuit 2 which finds the real number part of discrete Fourier transformation DFT, and a circuit 3 which finds the imaginary number part of the DFT. While the circuits 2 and 3 are in normal operation, the output of a circuit 6 which finds the absolute value of a discrete Fourier transformation output is fixed with out reference to its phase. If however, the circuit 2 has a fault to cease its output 4, the output of the circuit 6 becomes equal to that of the circuit 3, and when the circuit 3 has a fault, the output of the circuit 6 becomes equal to the output 4 of the circuit 2. For the purpose, a relation between the threshold value 8 and phase of a comparing circuit 9 is selected adequately; when both the circuits operate normally, the output 7 of the circuit 6 increases above the threshold value 8 and when either one of the circuits 2 and 3 has a fault, the output 7 of the circuit 6 becomes less than the threshold value 8, so that the fault is detected.
JP56029714A 1981-03-02 1981-03-02 Self-testing system for multifrequency signal receiver Granted JPS57143970A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56029714A JPS57143970A (en) 1981-03-02 1981-03-02 Self-testing system for multifrequency signal receiver

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56029714A JPS57143970A (en) 1981-03-02 1981-03-02 Self-testing system for multifrequency signal receiver

Publications (2)

Publication Number Publication Date
JPS57143970A true JPS57143970A (en) 1982-09-06
JPH0343819B2 JPH0343819B2 (en) 1991-07-03

Family

ID=12283770

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56029714A Granted JPS57143970A (en) 1981-03-02 1981-03-02 Self-testing system for multifrequency signal receiver

Country Status (1)

Country Link
JP (1) JPS57143970A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS52106614A (en) * 1976-03-04 1977-09-07 Fujitsu Ltd Signal detection

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS52106614A (en) * 1976-03-04 1977-09-07 Fujitsu Ltd Signal detection

Also Published As

Publication number Publication date
JPH0343819B2 (en) 1991-07-03

Similar Documents

Publication Publication Date Title
JPS56140452A (en) Memory protection system
GB1019416A (en) Improvements relating to testing equipment
JPS56169481A (en) Inspection signal analyzer in catv system
GB843225A (en) Improvements in or relating to electrical systems for determining the condition of electrical devices
JPS57143970A (en) Self-testing system for multifrequency signal receiver
KR920018774A (en) Test signal output circuit for LSI
DE3467418D1 (en) Interface checking apparatus
DE69309694T2 (en) DETECTION OF FAULTS IN POWER LINE
JPS5731058A (en) Fault diagnostic system of digital circuit
JPS5715296A (en) Testing system for storage device
JPS57194378A (en) Test circuit of electronic clock
JPS575134A (en) Automatic resetting circuit system
JPS5730039A (en) Error processing system
JPS57168531A (en) Echo erasing device
JPS57114872A (en) Detecting and display device
JPS5775054A (en) Testing system for digital coference telephone connection device
JPS55124849A (en) Error detection control system
KR920008592A (en) Finite-state machines for reliable calculation and adjustment systems
JPS57139815A (en) Fault diagnostic device
JPS54130822A (en) Line concentrator of analogue line
JPS5483353A (en) Protective circuit of amplifier
JPS57212539A (en) Arithmetic device
JPS5214846A (en) Unbalance detection relaying system
JPS5317294A (en) Fault alarm circuit
JPS55163465A (en) Aging tester