User`s guide

68 Chapter 8 Special Features: Modem Emulation
the remote side closes the TCP connection.
In Diagram B, two Digi devices will replace modems on both sides of the
connection. The initiation of the connection occurs with either of the Digi
devices. If both ends are Digi devices, the TCP listening port number is
50001 for port 1. An example of the connection command is ATDT
192.168.25.30:50001. Upon establishing a successful TCP
connection, a CONNECT message is sent to the serial port and only then
does the Digi device switch from AT command mode to data mode. After
the CONNECT is received, the transmission of data begins. Using the
modem escape sequence or dropping DTR on either side terminates the
connection.
Modem Emulation Cable Signals
Use the following signal assignments to make a cable connecting the Digi
device to a serial device.
DSR and DTR on the serial device side are connected to the DSR signal of
the Digi device.
Scenarios for Modem Emulation
Outgoing Modem Emulation Connection
Serial device sends ATDx.x.x.x:y command, which triggers the Digi device
to establish a telnet connection to destination IP=x.x.x.x, port=y.
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192.168.25.30
Workstation
Digi One TS
#1
Digi One TS
#2
Ethernet
Serial cable
User Scenario-Diagram B
Serial cable
Workstation