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SDS2100 User Guide
3: Configuring the Unit
5. For Retrytimeout, enter the number of seconds the unit should wait before failing
an attempted connection.
Modem (Emulation) Mode:
In Modem Mode, the unit presents a modem interface
to the attached serial device. It accepts AT-style modem commands, and handles the
modem signals correctly.
Normally there is a modem connected to a local PC and a modem connected to a
remote machine. A user must dial from the local PC to the remote machine,
accumulating phone charges for each connection. Modem Mode allows you to
replace modems with SDS2100s, and to use an Ethernet connection instead of a
phone call, without having to change communications applications and make
potentially expensive phone calls.
To select Modem Mode, set the Connect Mode to
C6
(no echo),
D6
(echo with full
verbose), or
D7
(echo with 1-character response).
Note:
If the unit is in Modem Mode and the serial port is idle, the unit can
still accept network TCP connections to the serial port if Connect Mode is set
to C6 (no echo), D6 (echo with full verbose), or D7 (echo with 1-character
response).
In Modem Mode, echo refers to the echo of all of the characters entered in command
mode; it does not mean to echo data that is transferred. Quiet Mode (no echo) refers
to the modem not sending an answer to the commands received (or displaying what
was typed).
To disconnect a connection using Modem Mode commands:
There must be a 1-second guardtime (no data traffic) before s++.
There must not be a break longer than 1 second bs.
There must be another 1-second guardtime after the last + is sent.
The unit acknowledges with an
OK
to indicate that it is in command mode.
Enter
ATH
and press
Enter
. It is echoed if echo is enabled. ATH is
acknowledged by another
OK
.
Table 3-8. Modem Mode Commands
Modem Mode Command
Function
ATDTx.x.x.x,pppp or ATDTx.x.x.x/pppp
Makes a connection to an IP address (x.x.x.x) and a
remote port number (pppp).
ATDTx.x.x.x
Makes a connection to an IP address (x.x.x.x) and the
remote port number defined within the unit.
ATD0.0.0.0
Forces the unit into monitor mode if a remote IP
address and port number are defined within the unit.
ATD
Forces the unit into monitor mode if a remote IP
address and port number
are not
defined within the
unit.
ATDx.x.x.x
Makes a connection to an IP address (x.x.x.x) and the
remote port number defined within the unit.
ATH
Hangs up the connection (Entered as
+++ATH
).
ATDTx.x.x.x,pppp or ATDTx.x.x.x/pppp
Makes a connection to an IP address (x.x.x.x) and a
remote port number (pppp).
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