Silicon Laboratories SI2494/39 manual Wait for Receiver to answer with handshake tones, Message

			AN93
	Table 145. Ademco® Mode of Operation (Continued)
Step	DTE-to-Modem Command	Modem-to-DTE	Remarks
		Indication
7	AT:U181,78,0,0,1C	OK	Set up 1400 Hz detector to
			detect 100 ms Handshake tone
			burst.
8	ATDnnnnnnn	OK	Call RECEIVER station.
9	AT+VTD=5;:U48,32	OK	Change DTMF on off time to pre-
			pare for Data Tones transmis-
			sion.
10	Wait for RECEIVER to answer with handshake tones
11		<DLE><c>	1400 Hz tone burst detected
		i.e. 0x10, 0x63	Note: First part of Handshake
			Tones detected.
12		<DLE><e>	2300 Hz tone burst detected
		i.e. 0x10, 0x65	Notes: Second part of Hand-
			shake Tones detected.
			Since there is a 100 ms silence
			between the 1400 Hz and
			2300 Hz tones, the <DLE><e>
			message should come nomi-
			nally 200msec after the previous
			<DLE><c> message.
			It is the responsibility of the host
			DTE driver to measure and vali-
			date this time period.
13	AT:U181,334,0,0,12C	OK	Change 1400 Hz detector to
			detect 800 ±300 ms tone burst,
			i.e. Kissoff tone.
14	Delay 250 ms before transmitting Data Tones		Host DTE should adjust this
	message.		delay so that the following +VTS
			DTMF transmission will start
			between 250 to 300 ms after the
			reception of <DLE><e> above.

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