SI2457-C-FT Silicon Laboratories Inc, SI2457-C-FT Datasheet - Page 21

• Manufacturer Part Number: SI2457-C-FT
• Description: IC ISOMODEM SYSTEM-SIDE 24TSSOP
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2457-C-FT

• Package / Case: 24-TSSOP
• Mfg Application Notes: SI2493/57/34/15/04, Appl Note AN93
• Data Format: V.21, V.22, V.23, V.32, V.34, V.90, Bell 103, Bell 212A
• Baud Rates: 56k
• Interface: Parallel, UART
• Voltage - Supply: 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Operating Frequency: 4.92 MHz
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 3 V
• Supply Current: 26 mA
• Operating Temperature Range: 0 C to + 70 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

$
A
A/
Dn
En
E0
E1
Hn
H0
Command
Table 11. Basic AT Command Set (Command Defaults in Bold)
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
Enable
Hook switch.
Go on-hook (hang up modem).
Modifier
! or &
, or <
@
W
G
P
T
L
;
Preliminary Rev. 0.7
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
Wait for silence.
Polarity reversal detect. By placing the “G” character in
the dial string (i.e. ATDTG1), the Si2457/34/15/04 will
monitor the telephone line for polarity reversals. If a
busy tone is detected, the Si2457/34/15/04 will report
“POLARITY REVERSAL” if a polarity reversal was
detected or “NO POLARITY REVERSAL” if a polarity
reversal was not detected. In each case, the result
code is followed by “OK”. If the S7 timeout occurs
before a busy tone is detected, the Si2457/34/15/04
will report “NO CARRIER”. Polarity reversal monitoring
begins after the last digit is dialed and ends when the
busy tone is detected or S7 timeout occurs.
Note: It is not possible to establish a modem connection
Redial last number.
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” com-
mand 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.
Si2457/34/15/04-Si3008
Action
when using this command.
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