GB1532103A - Method and apparatus for translating multiple frequency signalling - Google Patents

Method and apparatus for translating multiple frequency signalling

Info

Publication number
GB1532103A
GB1532103A GB7674/77A GB767477A GB1532103A GB 1532103 A GB1532103 A GB 1532103A GB 7674/77 A GB7674/77 A GB 7674/77A GB 767477 A GB767477 A GB 767477A GB 1532103 A GB1532103 A GB 1532103A
Authority
GB
United Kingdom
Prior art keywords
signals
band
low
high band
frequency
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.)
Expired
Application number
GB7674/77A
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.)
Nortel Networks Ltd
Original Assignee
Northern Telecom 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 Northern Telecom Ltd filed Critical Northern Telecom Ltd
Publication of GB1532103A publication Critical patent/GB1532103A/en
Expired 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
  • Stereo-Broadcasting Methods (AREA)

Abstract

1532103 Frequency detection NORTHERN TELECOM Ltd 23 Feb 1977 [3 March 1976] 07674/77 Heading G4H A multiple frequency signalling receiver comprises input means 1-2 for receiving voice frequency signals; means 2a, 2b for filtering the received signals into separate high and low bands; means, e.g. 18-19, for generating high band and low band threshold levels 16a, 16b in response to the amplitudes of signals in the high and low bands respectively; a high band detector 10a including a high band digital circuit 20 for detecting ones of predetermined frequencies of the signals in the high band and for indicating the frequency detected; first means 15 responsive to the low band threshold level 16b to transmit to the high band digital circuit only those signals in the high band which exceed the level 16b; a low band detector 10b including a low band digital circuit for detecting ones of predetermined frequencies of the signals in the low band and for indicating the frequency detected; second means responsive to the high band threshold level 16a to transmit to the low band digital circuit only those signals in the low band which exceed level 16a; and output means 6, 25, 28, &c. for indicating the frequencies detected in response to a simultaneous and constant indication of frequency detection from both detectors extended over a predetermined period of time.
GB7674/77A 1976-03-03 1977-02-23 Method and apparatus for translating multiple frequency signalling Expired GB1532103A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA247,035A CA1031086A (en) 1976-03-03 1976-03-03 Method and apparatus for translating multiple frequency signalling

Publications (1)

Publication Number Publication Date
GB1532103A true GB1532103A (en) 1978-11-15

Family

ID=4105372

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7674/77A Expired GB1532103A (en) 1976-03-03 1977-02-23 Method and apparatus for translating multiple frequency signalling

Country Status (11)

Country Link
JP (1) JPS52107708A (en)
AU (1) AU508271B2 (en)
BE (1) BE852056A (en)
CA (1) CA1031086A (en)
DE (1) DE2709370A1 (en)
DK (1) DK88877A (en)
FR (1) FR2343377A1 (en)
GB (1) GB1532103A (en)
NL (1) NL186057C (en)
NO (1) NO770696L (en)
SE (1) SE424129B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5831140B2 (en) * 1978-11-10 1983-07-04 株式会社日立製作所 signal receiver
DE3629907A1 (en) * 1986-09-03 1988-03-10 Standard Elektrik Lorenz Ag SIGNALING RECEIVER

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3743945A (en) * 1970-12-23 1973-07-03 Itt Limiter for multi frequency voice receiver
FR2127450A5 (en) * 1971-03-03 1972-10-13 Ibm France
DE2116635C3 (en) * 1971-04-05 1978-10-05 Ibm Deutschland Gmbh, 7000 Stuttgart Method for digital decoding of frequency-coded signals and circuit arrangement for carrying out the method
CA976675A (en) * 1972-10-16 1975-10-21 Microsystems International Limited Dual tone receiver
US3914557A (en) * 1973-04-11 1975-10-21 Bell Telephone Labor Inc Multifrequency tone detecting arrangement
US3936801A (en) * 1974-09-12 1976-02-03 Bell Telephone Laboratories, Incorporated Multifrequency signal receiver timing circuit

Also Published As

Publication number Publication date
DK88877A (en) 1977-09-04
AU508271B2 (en) 1980-03-13
SE7702418L (en) 1977-09-04
AU2244877A (en) 1978-08-24
NL7702219A (en) 1977-09-06
JPS52107708A (en) 1977-09-09
FR2343377A1 (en) 1977-09-30
DE2709370A1 (en) 1977-09-08
NO770696L (en) 1977-09-06
NL186057C (en) 1990-09-03
FR2343377B1 (en) 1983-08-12
SE424129B (en) 1982-06-28
NL186057B (en) 1990-04-02
CA1031086A (en) 1978-05-09
BE852056A (en) 1977-07-01

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee