Method and apparatus for detecting an escape sequence in a modem
US5530718A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1994 |
| Grant date | Jun 25, 1996 |
| Priority date | — |
| Expiry date | Apr 7, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M11/06
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for detecting an escape sequence to cause a modem to switch from a data transmission mode to a command mode. The escape sequence precedes a command instruction. The escape sequence comprises a first predetermined set of characters and a second predetermined set of characters. The method comprises the steps of temporarily storing in succession in a memory M characters received by the modem from a host computer; detecting whether the memory contains in contiguous manner the first and second sets of characters; leaving the modem in data transmission mode if the memory does not contain the contiguous occurrence of the first and second predetermined sets of characters; if the memory does contain the contiguous occurrence of the first and second predetermined sets of characters, detecting whether an end-of-instruction code is to be found in the N characters following the first and second contiguous predetermined sets of characters; leaving the modem in a transmission mode if the end-of-instruction code is not detected in said N characters; and if the end-of-instruction code is detected in said N characters, authorizing the modem to switch from data transmission mod…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.