Error-control Mode &Q5
The error-control mode is a feature available only between Hayes V-series
products, and other modems supporting particular protocols (e.g., ITU-T
V.42). This mode provides error control for errors that may occur during
transmission. When operating in this mode, the modem implements one of the
error-control protocols that can be negotiated with the remote modem.
If the modem receives a character while dialing the telephone number, it
aborts the call and sends the OK result code; if a character is received
after dialing but prior to the completion of the connection, it aborts the
call and sends the NO CARRIER result code. For the responses associated
with transitions of the DTR signal for this mode, see the &D command.
The following diagram illustrates modem operation in error-control mode:
Error-control mode is automatically selected in &Q5 communication mode (factory
setting).