Z02205 Datasheet, PDF (14/30 Pages) Zilog, Inc. – MODEM CONTROLLER IDEAL FOR LOW POWER CONSUMPTION, SMALL SIZE REQUIREMENTS

Z02205
Modem Controller
Command
D
Dial
&D
Data Terminal Ready
Options
ZiLOG
Table 2. AT Command Set (Continued)
Function and Description
The D command causes the modem to dial a telephone call according to the digits and
dial modifiers in the dial string following the command. Any commands following the
dial string on a command line are ignored, unless the semicolon dial modifier is the last
character in the dial string. If the modem is off-hook when the Dial command is given,
the modem dials immediately without trying to detect a dial tone. Characters other than
digits and dial modifiers in a dial string are ignored; however, they are counted as
characters in the command line buffer.
If line current sensing is enabled, and line current is detected before the modem is taken
OFF-HOOK when the modem dials, a NO CARRIER result code is displayed and the
modem enters the IDLE state. If the modem needs not dial (that is, ATD with no dial
string), the modem assumes the call was manually established and attempts to make a
connection.
The D command is not valid when the modem is in the On-Line state.
See “Dial Modifiers and “Modem Result Codes for more information.
&D determines how the modem responds to the DTR signal from the terminal. The
country configuration may prevent the modem from detecting terminal DTR. In this
case, the modem assumes DTR is always on. In North America, terminal DTR is
normally detected. If DTR detection has been prevented, the modem will respond with
an ERROR result to this command.
The response to changes in DTR also depends on the &Q and &D commands. This table
defines what happens when DTR goes off for all possible combinations of the &D and
&Q commands. To see what happens when DTR goes on, refer to the &Q command. The
default value is &D0 in North America:
&D0
&D1
&D2
&D3
&Q0
None
B
C
D
&Q1
A
B
C
D
A
The modem hangs up the telephone line and issues an OK result code.
B
If in the On-Line state, the modem goes into the Command state, and issues
an OK result code.
C
The modem hangs up the telephone line and issues an OK result code.
Auto-Answer is disabled as long as DTR stays off.
D
The modem resets.
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PS001000-MOD0599