Multi-Tech Systems MTA128NT - Manual (Page 32)

AT Commands, S-Registers, and Result Codes
MTA128ST/NT 32
• Data Mode—MTA128ST/NT enters data mode when it makes a successful data communications link with
a remote device. In data mode, the TA can send and receive data, but it does not respond to AT
commands. Instead it treats them as data and transmits them to the remote device.
• Online Command Mode—MTA128ST/NT responds to AT commands while maintaining a data
communications link; however, transmission of data is suspended. To enter online command mode from
data mode, type the escape sequence +++AT<cr>. To return to data mode from online command mode,
type ATO<cr>.
Making a Call
Before you can place a data call, configure the MTA128ST/NT for the local switch type, serial port speed,
and the data type of the ISDN device you want to call. See Chapter 3, Configuration Utilities.
Dialing
To dial a number using AT commands, you must first start a data communications program. In the
program’s terminal mode, type ATDxxxxxxx<cr>, where xxxxxxx is the telephone number you want to
dial, and <CR> is the carriage return character that is sent when you press the ENTER key, such as
ATD7853500<cr>. The dial string can contain up to 80 characters.
To place an ML-PPP call, use an ampersand character ( &) to join two telephone numbers, such as
ATD7853500&7853502<cr>. The telephone numbers can be the same or different. Using this method, two
B-channels are activated to transmit data at an aggregate speed of 128 Kbps.
To make it easier to read the dial string, you can use hyphens, spaces or parentheses. These characters
are ignored by the MTA128ST/NT. For example, the MTA128ST/NT would read the following dial strings the
same way:
ATD17637853500 <cr>
ATD 1-763-785-3500 <cr>
ATD 1 (763) 785-3500 <cr>
Channel Bundling Flag Dialing
The command AT&Jn is used to indicate whether outgoing calls should be made on two B-channels by
default. The command AT&J1&W0<cr>, configures the TA to place a call, dialing on two B-channels by
default. If no second number is given in the dial string, that single number is dialed twice. This
compensates for the interworking issues with Windows Dial-Up Networking. On the other hand, if the user
explicitly indicates two numbers in the dial string, then two numbers are dialed (e.g., ATD7853500&785
3502<cr>). The command AT&J0&W0<cr>, disables automatic call bundling. Note other valid characters
joining two telephone numbers include a plus sign (+), and an exclamation mark (!).
Note: In Windows Dial-Up Networking, if the Use Country Code and Area Code box is checked in the
Properties window for dial-up connection, the bundling modifier (i.e., &, + or !) is removed from the
dialing string when the user attempts to make a connection. The solution is to not check the
Use Country
Code and Area Code box or to simply add the bundling dial modifier to the phone number at the time of
connection.
Canceling a Call
To cancel a call before the MTA128ST/NT makes a connection, press any key.
Storing a Telephone Number
To store a telephone number, type &Zn=x in terminal mode, where n is the number of the memory register
in which the number is to be stored, and x is the dial command string that you want to store. For example,
type AT&Z9=763-785-3500 <cr> to store the number 763-785-3500 in memory register 9.
Dialing a Stored Telephone Number
To dial a stored telephone number, type DSn in terminal mode, where n is the location of the number you
wish to dial. For example, type ATDS3 <cr> dials a telephone stored in memory register 3 location.