Silicon Laboratories SI2494/39, SI2493/57/34/15/04 manual SMS Process in Host and Modem

AN93

For Figure 39, assume that the originating modem transmits first and that the two modems alternate transmitting and receiving. For simplicity, this figure does not show the provisions for timeout cases.

						HES = 1
					AT+FCLASS = 256
					(V .2 3 half -duple x )
			ATDTxxxx ;		O	Orig ina te	A
						?	ATDT ;
			OK				OK
		1	Pr otocol	2			AT +FRM =200
			?
		AT+FTM =201			AT + FTM = 202
							CONNECT n
		CONNECT			CONNEC T		n = 1 o r 2
	N	Data received		N	Data received
		from Host			from Host		Receive messag e ,
		?			?
							send to Host
		Y			Y
		80 bits of mark			30 0 bits channel
					seizure
					( alternating	1 's &	OK
		Host sends			0's)
		message followed
		by 15 0 ms o f
		silence , then ESC			80 bits of mark
					Host sends
	N	ESC to			message followed
Send Marks					by 15 0 ms of
		Command
					silence , then ESC
		Mod e
		?
		Y
				N	ESC to
			Send Marks		Command
					Mode
					?
					Y		Implicit +FRM

Figure 39. SMS Process in Host and Modem

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