Silicon Laboratories SI2494/39 Specifies action taken if an underrun condition occurs, Frame, Off

AN93

Table 39. Basic AT Command Set (Continued)
Command		Action
	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
+ESA =	frame.
A,B,C,D,E,F,G		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)
	Class 1 Mode Enable.
	X	Mode
+FCLASS = X	0	Off
	1	Enables support for V.29 Fast Connect mode.
	8	Enables voice mode.
	256	SMS mode
	Class 1 Receive Carrier.
	X	Mode
	2	Detect V.21 (980 Hz) tone for longer than 100 ms, then
		send answer tone
+FRM = X		(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.

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