Specifications

Si2457/34/15/04
26 Rev. 1.3
+ESA Options
+ESA = A
+ESA = A,B
+ESA = A,B,C
+ESA = A,B,C,E
+ESA = A,B,C,E,F
+ESA = A,B,C,E,F,
G
Synchronous access mode control options
A Specifies action taken if an underrun condition occurs during transparent sub-mode.
0 Modem transmits 8-bit SYN sequences on idle.
B Specifies action taken if an underrun condition occurs after a flag during framed sub-
mode
0 Modem transmits 8-bit HDLC flags on idle.
C Specifies action taken if an underrun or overrun condition occurs after a non-flag during
framed sub-mode.
0 Modem transmits abort on underrun in middle of frame.
1 Modem transmits flag on underrun in middle of frame and notifies host of underrun
or overrun.
D Specifies V.34 half duplex operation.
This parameter should not be used.
E Specifies CRC polynomial used while in framed sub-mode.
0 CRC generation checking disable.
1 16-bit CRC generation and checking is performed by the modem.
F Specifies NRZI encoding and decoding.
0 NRZI encoding and decoding disabled.
G Specifies SYN.
255
+FCLASS = X
Class 1 Mode Enable for V.29 fast connect.
X
Mode
0Off
1 Enables support for Class 1 mode for use in the V.29 fast connect mode.
+FRM = X
Class 1 Receive Carrier for V.29 fast connect.
X
Mode
2 Transmit V.21 (980 Hz) tone for longer than 100 ms, then send answer tone
(2100/2225 Hz) for 200 ms.
95 V.29 short synchronous.
96 V.29 full synchronous.
+FTM = X
Class 1 Transmit Carrier for V.29 fast connect.
X
Mode
2 Transmit V.21 (980 Hz) tone.
53 Same as &T4, but transmit V.29 7200 bps. Data pattern set by S40 register. AT +
FCLASS = 0 must be sent to restore the ISOmodem
®
to normal operation after
test.
54 Same as &T4, but transmit V.29 9600 bps. Data pattern set by S40 register. AT +
FCLASS = 0 must be sent to restore the ISOmodem to normal operation after test.
95 V.29 short synchronous.
96 V.29 full synchronous.
Table 8. Basic AT Command Set (Command Defaults in Bold) (Continued)
Command Action