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Si2494/39
Rev. 1.0
31
+DS44 Options
+DS44 = A
+DS44 = A,B
+DS44 = A,B,C
Controls V.44 data compression function.
A
Direction
0 No compression
1 Transmit only
2 Receive only
3
Both Directions
B
Compression_negotiation
0
Do not disconnect if V.44 is not negotiated.
1 Disconnect if Rec. V.42 is not negotiated.
C
Capability
0 Stream method
+ES Options
+ES = A
+ES = A,,C
Enable synchronous access mode.
A
Specifies the mode of operation when initiating a modem connection.
D Disable synchronous assess mode.
6 Enable synchronous access mode when connection is completed and data state is
entered.
B
Specifies fallback mode of operation.
This parameter should not be used.
C
Specifies the mode of operation when answer a modem connection.
D Disable synchronous assess mode.
8 Enable synchronous access mode when connection is completed and data state is
entered.
+ESA Options
+ESA = A
+ESA = A,B
+ESA = A,B,C
+ESA = A,B,C,E
+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
0
Data (limited to configuration only, data calls prohibited)
1
Enables support for Class 1 mode for use in the V.29 fast connect mode.
8
Voice mode
Table 10. Basic AT Command Set (Command Defaults in Bold) (Continued)
Command
Action