Reference Guide for the Model XM128 ISDN Digital Modem
ISDN Overview 6-3
Conventional dialing commands ATD, ATDT, and ATDP, used by much of the existing
communication software, can be mapped onto one of the new dialing commands according
to the AT&O setting as shown in Table6-1.
The factory default is AT&O2, which means that the Model XM128 modem selects ISDN data
mode when you do not specify the communication mode to use (that is, ATD or ATDT).
Placing the CallTo initiate a call, choose the proper communication mode and configure the mode according to
the bearer service (or protocol) you want to use. Ta ble 6-2 contains some simple commands that
are useful when placing a call.
Table6-1 . Dialing commands
AT Command Dial string it maps to
AT&O0 ATD, ATDT, and ATDP are the same as ATDB.
AT&O2 ATD, ATDT, and ATDP are the same as ATDI.
AT&O3 ATD, ATDT, and ATDP are the same as ATDA.
Table6-2 . Call placing commands
Command Description
ATBnn Changes ISDN B channel protocol setting
ATDL Redials the last dialed telephone number