Silicon Laboratories SI2493/57/34/15/04 - Manual (Page 67)

AN93
Rev. 1.3 67
+ESA =
A,B,C,D,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 (see
+ESA[G]) 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 – Defines 8-bit SYN
255 = Fixed at 255 (marks)
+FCLASS = X
Class 1 Mode Enable.
X
Mode
0 Off
1 Enables support for V.29 Fast Connect mode.
8 Enables voice mode.
256 SMS mode
+FRM = X
Class 1 Receive Carrier.
X
Mode
2 Detect 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.
200 Returns to data mode prepared to receive an SMS mes-
sage.
Table 39. Basic AT Command Set (Continued)
Command Action