Black Box MD1276A, User Manual

Page: 116 / 289

Page 116
AT&L Leased Line
The &L command allows you to specify whether your modem will be connecting over the
public switched telephone network (PSTN) or leased lines (point-to-point connection).
When the leased-line mode is selected, if the carrier from the remote modem is lost, the modem
will continuously attempt to re-establish a connection.
If you select leased line operation with the &L1 command, you must issue the ATA command to
answer a call, and the ATD command to initiate a call.
If you use the &L2 or &L3 command to select Auto leased line operation, you do not need to
issue the ATA or ATD commands; &L2 selects Originate mode automatically and &L3 selects
Answer mode automatically. The modem
’ s TALK/DATA switch must be set to DATA and DTR
must be raised to make the modem go off-hook and DTR lowered (or the TALK/DATA switch
is set to TALK) to return to local command state.
+
If your modem has a TALK/DATA switch, it must be set to DATA when using &L2 or
&L3.
See the section
— Leased Line Operations — for a detailed explanation of the &L command and
leased line operations.
+ UK Modems. Warning. Please ensure that the &L1, &L2 or &L3 command is issued
prior to establishing a connection across leased line circuits.
Options
AT&L0
n
PSTN mode
AT&L1 Leased-line mode
AT&L2 Auto leased line Originate mode
AT&L3 Auto leased line Answer mode
Range
0-3