公开(公告)号：FR2682549B1

公开(公告)日：1994-01-14

申请号：FR9112546

申请日：1991-10-11

Applicant: APPLE COMPUTER INC

Inventor： GRADELER ERIC ,  NICOLLE THIERRY ,  PHAM ALEXIS

IPC: H04M11/00 ,  H04M11/06 ,  H04L29/02

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 mode to command mode.