You can also use the pseudo-send STTY=value string to set modem characteristics. For instance, STTY=crtscts enables outbound hardware flow control. STTY=crtsxoff enables inbound hardware flow control. STTY=crtscts,crtsxoff enables both outbound and inbound hardware flow control.
STTY accepts all the stty modes. See the stty(1) and termio(7I) man pages.
The following example would enable hardware flow control in a Dialers entry:
dsi =,–, "" \dA\pTE1V1X5Q0S2=255S12=255*E1*F3*M1*S1\r\c OK\r \EATDT\T\r\c CONNECT\sEC STTY=crtscts
This pseudo-send string can also be used in entries in the Systems file.