SI2457-D-FT Silicon Laboratories Inc, SI2457-D-FT Datasheet - Page 226

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

Specifications of SI2457-D-FT

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

AN93
226
Table 142. AT Commands Provided to Support SIA Level-3 Protocol Communication (Continued)
AT+F1
AT+F2
AT+F3
AT+F4
AT+F5
AT+F6
AT Command
Enable B103 Receiver for Data Block
reception.
Enable tonal ACK/NACK detection.
Transmit Tonal ACK
Transmit Tonal NACK
Transmit Tonal ACK with reverse chan-
nel command.
Abort current Data Block Reception or
Transmission.
Modem Function
Rev. 1.3
Modem enables FSK receiver, waits for >12T marks
to be detected, then sends CONNECT message to
DTE to indicate a received Data Block follows.
Modem will stay in this mode indefinitely until an AT
command is issued by DTE. It is usually a
+F3(ACK), +F4(NACK) or +F5(ACK followed by
Data Block transmission) command.
Note1: Modem will wait for up to 1 second to detect
>12T marks before unclamping RXD. After 1 sec-
ond RXD will be unclamped regardless.
Note 2: The +F1 command can be used to resume
SIA protocol communication after a voice listen-in or
V.32bis interruption.
Detect and report ACK or NACK to DTE.
‘OK’ for ACK and ‘ERROR’ for NACK.
A NACK will be reported if no valid signal is
detected within 2.5 seconds.
Transmit Space for 600 ms. Send ‘OK’ prompt to
DTE when done.
Transmit Mark for 600 ms. Send ‘OK’ prompt to
DTE when done.
Transmit Space for 600 ms, followed by Mark for
180 ms. Then send CONNECT to DTE to indicate
modem is ready to accept data.
This command is useful for exception handling,
such as timeout. If the FSK transmitter was on, +F6
shuts it off. FSK reception is aborted and modem
returns to the AT command mode.
Remarks