Motorola V.34-SDC Autobaud Feature, Escape Sequence-+++, Valid Autobauding Character Formats

Autobaud Feature

The modem automatically detects the speed and character format of the following AT commands issued from your DTE:

•AT

•at

•A/

•a/

This means that any AT command you issue to the modem will cause the modem to “Autobaud.” The exception is the lower-case “a/” and upper-case “A/”, from which only speed can be detected. When the a/ or A/ commands are issued, the modem assumes parity to be the same as that of the previous command.

NOTE: Autobaud does not operate when the modem is online in escape mode. Autobauding works at the following DTE rates (bps):

300	1200	2400	4800	7200	9600
12,000	14,400	16,800	19,200	21,600	24,000
26,400	28,800	38,400	57,600	115,200

Table 5-2summarizes the 10-bit-total character formats for autobauding. (Autobauding is valid only with 10-bit character formats.)

Table 5-2.

Valid Autobauding Character Formats

Start Bit	Data Bits	Parity	Stop Bits
1	7	Even or Odd	1
1	7	None	2
1	7	Mark or Space	1
1	8	None	1

Result codes, such as RING, are sent at the last autobauded DTE speed and parity. CONNECT result codes are also sent at the last autobauded DTE speed, even if the call is established at a different speed. When the modem is turned on, the last autobauded speed is saved. Because parity is saved within option sets, the parity value that is saved in the power-up option set is the one that is active.

The Escape Sequence—(+++)

The escape sequence is used when the modem is online and you need to enter commands to the modem without disconnecting. The escape sequence with guard time protects against losing the connection while you send commands.

NOTE: Autobaud does not operate when the modem is in escape mode. Once in command state, you can:

•Terminate a call

•Initiate and terminate a test

•Issue AT action commands

•Change your modem’s configuration

•Initiate a remote configuration session

•Read modem status using the AT *ST command

Using the

AT ACU

Using the AT Automatic Calling Interface 5-5