GB2003704A - Digital data signalling systems - Google Patents

Digital data signalling systems

Info

Publication number
GB2003704A
GB2003704A GB7832530A GB7832530A GB2003704A GB 2003704 A GB2003704 A GB 2003704A GB 7832530 A GB7832530 A GB 7832530A GB 7832530 A GB7832530 A GB 7832530A GB 2003704 A GB2003704 A GB 2003704A
Authority
GB
United Kingdom
Prior art keywords
fsk
modulator
digital data
signalling systems
data signalling
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
GB7832530A
Other versions
GB2003704B (en
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.)
General Electric Co PLC
Original Assignee
General Electric Co PLC
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 General Electric Co PLC filed Critical General Electric Co PLC
Priority to GB7832530A priority Critical patent/GB2003704B/en
Publication of GB2003704A publication Critical patent/GB2003704A/en
Application granted granted Critical
Publication of GB2003704B publication Critical patent/GB2003704B/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying

Abstract

In a FSK signalling system arranged for two-way simplex operation over a telephone line, a terminal modem has a single notch filter (7) instead of the usual transmitting and receiving band-pass filters. This filter is on the input side of the FSK demodulator (6) and has maximum attenuation at the frequency supplied by the FSK modulator (3) when that modulator is not passing data. A gate (8) is arranged to suppress any signal supplied by the FSK demodulator (6) when the FSK modulator (3) is passing data. <IMAGE>
GB7832530A 1977-08-17 1978-08-08 Digital data signalling systems Expired GB2003704B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB7832530A GB2003704B (en) 1977-08-17 1978-08-08 Digital data signalling systems

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB3453077 1977-08-17
GB7832530A GB2003704B (en) 1977-08-17 1978-08-08 Digital data signalling systems

Publications (2)

Publication Number Publication Date
GB2003704A true GB2003704A (en) 1979-03-14
GB2003704B GB2003704B (en) 1982-01-20

Family

ID=26262321

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7832530A Expired GB2003704B (en) 1977-08-17 1978-08-08 Digital data signalling systems

Country Status (1)

Country Link
GB (1) GB2003704B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4449247A (en) * 1980-07-30 1984-05-15 Harris Corporation Local orderwire facility for fiber optic communication system
GB2148076A (en) * 1983-10-11 1985-05-22 Trane Co Microprocessor fsk data communications module
GB2173675A (en) * 1985-03-22 1986-10-15 Steven Henry Lerman Communication system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4449247A (en) * 1980-07-30 1984-05-15 Harris Corporation Local orderwire facility for fiber optic communication system
GB2148076A (en) * 1983-10-11 1985-05-22 Trane Co Microprocessor fsk data communications module
US4689801A (en) * 1983-10-11 1987-08-25 American Standard Inc. Microprocessor FSK data communications module
GB2173675A (en) * 1985-03-22 1986-10-15 Steven Henry Lerman Communication system

Also Published As

Publication number Publication date
GB2003704B (en) 1982-01-20

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee