AT&T 2230 - Manual (Page 11)

Set Dial Mode
NOTE: When you change the dial mode setting, BOTH handsets are
affected.
This phone comes set for touch tone (DTMF) dialing. If you have dial pulse
(rotary) service, set the dial mode to PULSE.
1 Press
S.
2 Press < until the screen displays
3 Press S. The screen displays
4 Press < or > to display DTMF or PULSE.
5 Press
S to save displayed setting.
FEATURE SETUP
9
>DIAL METHOD
CALL LOG
>DIAL METHOD
DTMF