Advantech EKI-1521 User Manual page 40

You might select "USDG Mode" as the following figure to change the mode of the port
to TCP server/client or UDP mode.
Protocol
The EKI-1500 series provides TCP/IP and UDP two protocols. In settings, you can
choose either TCP mode or UDP mode according to your application.
Data Listen Port
The TCP/UDP port number represents the source port number, and the number is
used to identify the channel for remote initiating connections. Range: 1024-65533. If
an unknown caller wants to connect to the system and asks for some services, they
need to define the TCP/UDP port to carry a long-term conversation.
Each node on a TCP/IP network has an IP address, and each IP address can allow
connections on one or more TCP port. The well known TCP ports are those that have
been defined; for example, port 23 is used for Telnet connections. There are also
custom sockets that users and developers define for their specific needs. The default
TCP/UDP port of the EKI-1500 series is 5300. The example initial 5300 is System
Port, and 5301 is Data Port. But users can adjust them by one's preference or appli-
cation.
Each port has its own data listen port to accept connected request of other network
device. So, the data listen port can't be set the same value. You can transmit/receive
data to/from device via the data listen port.
Command Listen Port
Each port has its own command listen port to accept connected request of other net-
work device. So, the command listen port can't be set the same value. You can use
'AT command' to change the port setting via the command listen port. The Command
Listen Port should be different from the Data Listen port.
EKI-1521/1522/1524 User Manual 34