JPS6418346A - Data terminal protector - Google Patents

Data terminal protector

Info

Publication number
JPS6418346A
JPS6418346A JP17386287A JP17386287A JPS6418346A JP S6418346 A JPS6418346 A JP S6418346A JP 17386287 A JP17386287 A JP 17386287A JP 17386287 A JP17386287 A JP 17386287A JP S6418346 A JPS6418346 A JP S6418346A
Authority
JP
Japan
Prior art keywords
data terminal
filter
frequency
terminal equipment
signal
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
JP17386287A
Other languages
Japanese (ja)
Inventor
Katsuo Tadachi
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.)
MIRAI BILL KENKYU KAIHATSU KK
MIRAI BIRU KENKYU KAIHATSU KK
Original Assignee
MIRAI BILL KENKYU KAIHATSU KK
MIRAI BIRU KENKYU KAIHATSU KK
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 MIRAI BILL KENKYU KAIHATSU KK, MIRAI BIRU KENKYU KAIHATSU KK filed Critical MIRAI BILL KENKYU KAIHATSU KK
Priority to JP17386287A priority Critical patent/JPS6418346A/en
Publication of JPS6418346A publication Critical patent/JPS6418346A/en
Pending legal-status Critical Current

Links

Landscapes

  • Sub-Exchange Stations And Push- Button Telephones (AREA)

Abstract

PURPOSE:To protect a data terminal equipment from malfunction by a service signal without modifying an exchange system by inserting a filter as a data terminal protection device between the data terminal equipment and an exchange. CONSTITUTION:A filter 11 or 11' is provided to the pre-stage or in the inside of a communication MODEM 16. A service tone signal St (such as long time call warning) incoming to a data terminal equipment 17 via a MODEM 16 is generated from a tone generator 18 in a private branch of exchange 13, interrupts an extension and is made effective only to a telephone set 15 but harmful to the terminal equipment 17. Then the band of the frequency of a data communication signal Sd is limited to f1 f and when the frequency of the signal St is f2, an HPF is used as the filter 11(11') and the lower limit frequency is set between the frequency f2 and f1- f. The hatch part shown in figure represents the cut-off area and the other shows the talking area. Thus, the filter 11(11') is used as a data terminal protection device.
JP17386287A 1987-07-14 1987-07-14 Data terminal protector Pending JPS6418346A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP17386287A JPS6418346A (en) 1987-07-14 1987-07-14 Data terminal protector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP17386287A JPS6418346A (en) 1987-07-14 1987-07-14 Data terminal protector

Publications (1)

Publication Number Publication Date
JPS6418346A true JPS6418346A (en) 1989-01-23

Family

ID=15968519

Family Applications (1)

Application Number Title Priority Date Filing Date
JP17386287A Pending JPS6418346A (en) 1987-07-14 1987-07-14 Data terminal protector

Country Status (1)

Country Link
JP (1) JPS6418346A (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58154955A (en) * 1982-03-10 1983-09-14 Fujitsu Ltd Preventing system of malfunction
JPS6115869B2 (en) * 1977-03-14 1986-04-26 Thomae Gmbh Dr K

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6115869B2 (en) * 1977-03-14 1986-04-26 Thomae Gmbh Dr K
JPS58154955A (en) * 1982-03-10 1983-09-14 Fujitsu Ltd Preventing system of malfunction

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