JPS57185749A - Method and apparatus for self-test of modulation and demodulation device - Google Patents

Method and apparatus for self-test of modulation and demodulation device

Info

Publication number
JPS57185749A
JPS57185749A JP56069370A JP6937081A JPS57185749A JP S57185749 A JPS57185749 A JP S57185749A JP 56069370 A JP56069370 A JP 56069370A JP 6937081 A JP6937081 A JP 6937081A JP S57185749 A JPS57185749 A JP S57185749A
Authority
JP
Japan
Prior art keywords
data
transmission
reception
signal
test pattern
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
JP56069370A
Other languages
Japanese (ja)
Inventor
Tsunetaro Sakai
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.)
Toshiba Corp
Original Assignee
Toshiba Corp
Tokyo Shibaura 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 Toshiba Corp, Tokyo Shibaura Electric Co Ltd filed Critical Toshiba Corp
Priority to JP56069370A priority Critical patent/JPS57185749A/en
Publication of JPS57185749A publication Critical patent/JPS57185749A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/24—Testing correct operation
    • H04L1/242—Testing correct operation by comparing a transmitted test signal with a locally generated replica
    • H04L1/243—Testing correct operation by comparing a transmitted test signal with a locally generated replica at the transmitter, using a loop-back

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
  • Maintenance And Management Of Digital Transmission (AREA)

Abstract

PURPOSE:To check a modulation and demodulation device before data transmission, by automatically discriminating if data are transmitted and transmitting/receiving a test pattern in the device within the device automatically if the data are not transmitted. CONSTITUTION:At the transmission of normal data, a transmission request RS and a transmission data signal SD are inputted from a communication controlling device or a terminal device, an output of an NOR gate NOG is 0 and selection circuits SECs 1 and 2 respectively select the transmission data SD and a reception data RD' for transmission and reception. If no data transmission is made, the signals RS and RD' are absent, a gate GAT is closed, an output of the NOG goes to 1, a test pattern signal TD is outputted from the selection circuit SEC1 and modulated at a modulator MOD, passes through the selection circuit SEC2 because the signal can not pass through the gate GAT, demodulated at a demodulator DEM and detects an error through the comparison with the original test pattern at an error detection circuit ERD. In this case, the reception data RD does not appear because of no output of a reception signal detecting circuit REC.
JP56069370A 1981-05-11 1981-05-11 Method and apparatus for self-test of modulation and demodulation device Pending JPS57185749A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56069370A JPS57185749A (en) 1981-05-11 1981-05-11 Method and apparatus for self-test of modulation and demodulation device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56069370A JPS57185749A (en) 1981-05-11 1981-05-11 Method and apparatus for self-test of modulation and demodulation device

Publications (1)

Publication Number Publication Date
JPS57185749A true JPS57185749A (en) 1982-11-16

Family

ID=13400597

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56069370A Pending JPS57185749A (en) 1981-05-11 1981-05-11 Method and apparatus for self-test of modulation and demodulation device

Country Status (1)

Country Link
JP (1) JPS57185749A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02158247A (en) * 1988-12-12 1990-06-18 Fujitsu Ltd Modem inspection system
JPH02246576A (en) * 1989-03-20 1990-10-02 Fujitsu Ltd Modulator/demodulator

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02158247A (en) * 1988-12-12 1990-06-18 Fujitsu Ltd Modem inspection system
JPH02246576A (en) * 1989-03-20 1990-10-02 Fujitsu Ltd Modulator/demodulator

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