Maxim Integrated 73M2901CE AT Command - Manual (Page 9)

UG_2901CE_027 73M2901CE AT Command User Guide
Rev. 2.0 9
DCD
ON
OFF
C1 – ON while connected
DCD
Connected Not connected Not Connected
V.23 turnaround
DCD V.23 turn around
2.5 D[n...n] – Dialing String
This command puts the modem into originate mode and instructs the modem to dial the phone number
expressed by the string argument n...n. The number will be dialed with either tones or pulses depending
on how the last number was dialed. On power up, this command will default to pulse dialing. (See the
note in DT[n...n] command.) The allowable arguments for n...n differ for pulse and tone dialing; see the
descriptions under DT[n...n] and DP[n...n].
DP[n...n] n = 0-9 , P T R ; @ ! W S[r]=[n]J5.[n]
This command instructs the modem to dial the phone number expressed by the argument n...n using
pulse dialing. (See the detailed description of the arguments under DT[n...n] below.)
DT[n...n] n = 0-9 A B C D * # , P T R ; @ ! W S[r]=[n]J5.[n]
This command instructs the modem to dial the phone number expressed by the argument n...n using tone
dialing.
In addition to 0-9 A B C D * #, which are the same as the keys on your phone, there are some special
characters that can be included in a dialing string. They are called Dial String Modifiers, and they define how
the phone number is to be dialed. These characters are P R T ; , @ ! W.
A-D*# The characters A B C D, and the symbols * and #, can be used only during tone dialing. They are
typically used to access newer features of modern telephone systems.
P The modem pulse dials the digits that follow.
R
The modem uses answer mode frequencies after dialing the number. This allows you to dial up an
originate only modem. Busy detect is disabled during Reverse Dial.
T The modem tone dials the digits, characters, and symbols that follow.
; A ; (semicolon) causes the modem to go back into the Command State, allowing you to enter other
commands while on-line. To do this, the ; must be the last character in the command line.
, When inserted in a dialing string, a , (comma) causes the modem to pause. The default time for the
pause is two seconds, and can be changed by modifying register S8.
@ A @ (commercial "at") causes the modem to wait up to 30 seconds for a 5 second period of quiet
before proceeding. This is often used to detect the end of a prerecorded message. The default wait