Modem Emulation Mode; Modem Mode Commands - Lantronix MSS4-D Installation Manual

Using the MSS

5.7 Modem Emulation Mode

In modem emulation mode, the MSS presents a modem interface to the attached serial
device: it accepts AT-style modem commands and handles the modem signals correctly.
The MSS forms a network connection based on the ATDT commands issued from the serial
device.
Normally there is a modem connected to a PC and a modem connected to some other
remote machine. A user must dial from his PC to the remote machine and accumulate
phone charges for each connection. With the MSS in modem mode, you can replace your
modems with MSS units and use an Ethernet connection instead of a phone call, all without
having to change communications applications. You can then connect to any remote
machine that has an MSS without making potentially-expensive phone calls.
If the MSS is in modem emulation mode and the serial port is idle, the
Note:
MSS can still accept network TCP connections to the serial port.
To use modem mode, enable modem emulation and set your MSS for Autostart using A as
the autostart character. This triggers the MSS to enter modem mode whenever it sees a
modem-style AT command.
Local>> CHANGE MODEM EMULATION ENABLED
Local>> CHANGE AUTOSTART CHARACTER "A"
Local>> LOGOUT PORT 1
As soon as someone types an AT command, the MSS will enter modem mode and begin
processing the AT commands. While in modem mode, the MSS will not display a
command line prompt.

5.7.1 Modem Mode Commands

The following commands are only available when the serial port is in Modem Emulation
mode—they will have no effect when entered at the Local> prompt.
Command
AT?
ATC <command>
ATDT <ipaddress>
Figure 5-16: Enabling Modem Emulation Mode
Table 5-2: Modem Mode Commands
Function
Help; gives list of valid AT commands.
Pass-through to normal command line interface..
Ex: ATC CH NAMESERV 192.0.1.76
Ex: ATDT 192.0.55.22:3001T
Ex: ATDT 192000055022:3001T
Users can specify sockets as well; in the examples, :3001T tells the MSS to
form a raw TCP connection to socket 3001.
Modem Emulation Mode
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