Hayes Microcomputer Products PC Card - Manual (Page 28)

DIVA T/A PC Card Reference Guide 28
General AT Commands—Continued
Command Description
+++ Escape Sequence: The escape sequence is
used to return to the command state from data
state. To issue the escape sequence, wait one
second then enter the escape character three
consecutive times (+++) and wait another
second. Its value is stored in S-Register 2.
The default value of the escape character as
stored in S-Register 2 is ‘+’.
?? Last AT Command Result Explained: The
?? command (no AT prefix required) reports
the result of the last AT command issued.
This command is useful for debugging long
strings of AT commands and for determining
which command was rejected and why.