User`s guide

Configure Digi devices
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TCP Sockets profile
The TCP Sockets profile allows serial devices to communicate over a TCP network. The TCP
Server allows other network devices to initiate a TCP connection to the serial device attached to
the serial port of the Digi device.
Automatic TCP connections (autoconnection)
The TCP Client allows the Digi device to automatically establish a TCP connection to an
application or a network, known as autoconnection. Autoconnection is enabled through the TCP
Sockets profile’s setting labeled Automatically establish TCP connections.
When the TCP Sockets profile is set, the DTR flow-control signal indicates when a TCP socket
connection has been established. This information can be useful in monitoring the serial line and
using it as a flow-control mechanism to determine when the Digi device is connected to a remote
device with which communication is being established. This mechanism can be combined with
using the DCD signal to close the connection and the DSR signal to do RCI over serial. Together,
these signals can be used to make the Digi device auto connect to many devices, deterministically,
on the network.
RFC 2217 support
Digi devices support RFC 2217, an extension of the Telnet protocol used to access serial devices
over the network. RFC 2217 implementations enable applications to set the parameters of remote
serial ports (baud rate, flow control, etc.), detect line signal changes, as well as receive and
transmit data. The configuration information provided in this section applies to Digi device
functioning as RFC 2217 servers. If using the RFC 2217 protocol, do not modify the port settings
from the defaults. If the port settings have been changed, restore the factory default settings (see
"Restore a device configuration to factory defaults" on page 156). No additional configuration is
required.
TCP and UDP network port numbering conventions
Digi devices use these conventions for TCP and UDP network port numbering.
The application or Digi device that initiates communication must use these network ports numbers.
If they cannot be configured to use these network port numbers, change the network port on the
Digi device.
For this connection type... Use this Port
Telnet to the serial port 2001 (TCP only)
Raw connection to the serial port 2101(TCP and UDP)