SI2414 SILABS [Silicon Laboratories], SI2414 Datasheet - Page 23

• Manufacturer Part Number: SI2414
• Manufacturer: SILABS [Silicon Laboratories]

AT Commands
At powerup, the Si2456/33/14 is in the AT Command
mode. In Command mode, the modem monitors the
input (serial or parallel) checking constantly for a valid
command (AT commands are described in Table 11).
Command Syntax
An AT command takes the form of a single letter or
combination of a letter and a modified character, often
followed by one or more numeric characters. The
modem interprets the AT command as a direction to set
a parameter or perform an action. The command (letter
or letter and modifier) identifies the parameter or action,
and the numeric value specifies (from a pre-determined
range of choices) how the parameter is to be set or how
the action is to be performed. Issuing any AT command
strings that are not listed in Table 11 may result in
unpredictable behavior.
AT commands are issued to the modem in the form of a
“command line.” Each command line is preceded by the
letters AT, contains one or more commands, and ends
Command
Dn
En
E0
A/
A
$
Display AT Command mode settings.
Answer incoming call
Re-execute last command. This is the only command not preceded by “AT” or followed by a <CR>.
Dial
The dial command, followed by 1 or more dial command modifiers, manually dials a phone number:
Local DTE echo
Disable
Table 11. Basic AT Command Set (Command Defaults in Bold)
Modifier
! or &
, or <
W
P
T
;
Rev. 0.9
Function
Flash hook switch for FHT (U4F) ms (default: 500 ms)
Pause before continuing for S8 seconds (default:
2 seconds)
Return to AT Command mode
Pulse (rotary) dialing—pulse digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
Tone (DTMF) dialing—DTMF digits: *, #, A, B, C, D, 0, 1, 2,
3, 4, 5, 6, 7, 8, 9
Wait for dial tone before continuing for S14 seconds
(default: 12 seconds). Blind dialing modes X0, X1 and X3
do not affect the W command.
If the DOP bit (U7A, bit 7) is set, the “ATDTW” command
will cause the ISOmodem to pause dialing and either report
an “OK” if a dialtone is detected or “NO DIALTONE” if a dial
tone is not detected.
with a carriage return. The letters AT stand for
“ATtention” and signal the modem that a command (or
commands) follows.
It is possible to enter multiple commands on a single
line (up to a maximum of 48 characters). The
commands may be separated by space or line-feed
characters to improve readability. The modem ignores
space and line-feed characters; so, they are not
counted as part of the line’s 48 characters. A carriage-
return character must be entered at the end of a
command line to signal the modem to process the
commands.
Command Buffer
Once the command line is issued to the modem, it is
loaded into an internal command buffer with a capacity
of 48 characters. The AT prefix, spaces, line-feed
characters, and carriage return are not loaded into the
buffer. If a command line is more than 48 characters
long, the modem does not act on any characters.
Action
Si2456/Si2433/Si2414
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