Motorola V.34-SDC ユーザーズマニュアル

Using the AT Automatic Calling Interface 5-5

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):

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

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 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

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

1

7

Even or Odd

1

1

7

None

2

1

7

Mark or Space

1

1

8

None

1