JPS6418346A - Data terminal protector - Google Patents
Data terminal protectorInfo
- 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
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.
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)
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 |
-
1987
- 1987-07-14 JP JP17386287A patent/JPS6418346A/en active Pending
Patent Citations (2)
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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