Black Box 3600 MODEM User Manual
AT Commands
Modem 3600
5-19
When distinctive ring is enabled, one of the messages in Table 5-3
appears on the DTE instead of the regular RING message:
appears on the DTE instead of the regular RING message:
Terminal Interface Commands
The EIA-232 interface connects the modem and DTE. Terminal
interface commands control the action of the modem and the terminal in
response to the signals being exchanged on the interface pins. Refer to
Table 2-1.
interface commands control the action of the modem and the terminal in
response to the signals being exchanged on the interface pins. Refer to
Table 2-1.
Data Carrier Detect &C
When using DCD to indicate a valid carrier, use the &C1 command.
Some terminals and other devices require DCD on in order to
communicate with the modem; if so, use the &C command.
Some terminals and other devices require DCD on in order to
communicate with the modem; if so, use the &C command.
Note
AT&C3
AT&C3
is used to simulate switched carrier operation.
Note
For simulated switched carrier operation &C3 must be
selected on both modems. Not available in the B103 and V.21
modulation modes.
For simulated switched carrier operation &C3 must be
selected on both modems. Not available in the B103 and V.21
modulation modes.
Table 5-3. Distinctive Ring Message s
The modem sends this
message...
message...
If the Ring Was a:
RING A
Single ring (1 ring burst)
RING B
Double ring (2 ring bursts)
RING C
Triple ring (3 ring bursts)
Command
Operation
&C
DCD always on
&C1
DCD on when modem recognizes remote modem
carrier or, if enabled, when protocol negotiation is
complete.
carrier or, if enabled, when protocol negotiation is
complete.
&C2
DCD on except for 5 seconds after disconnect
&C3
DCD follows RTS on remote modem (simulated
switched carrier V.13).
switched carrier V.13).