TCP Serial Server
The device will listen for an incoming TCP connection from a remote client. The port number of
the listening connection is specified in the RS-232 Service Port setting. Data received on the
TCP connection will be forwarded to the RS-232 port, and data received on the RS-232 port will
be forwarded to this TCP connection.
TCP Serial Client
The device will maintain a TCP client connection with a remote server. The IP address and port
number of the remote server are configured in the settings RS-232 TCP Serial Client IP Address
and RS-232 TCP Serial Client Port. Data received on the RS-232 port will be forwarded to this
TCP connection, and data received on the TCP connection will be forwarded to the RS-232
port. The device will attempt to open a connection with the remote server and if the connection
fails to open, the device will continue to retry at an interval of 60 seconds. If data arrives on the
RS-232 port when no TCP connection exists, the device will buffer the data (up to 1500 bytes)
and immediately attempt to open a connection to deliver the data. If the remote server closes
the connection due to error, the device will make a best effort to save any data that was in
process and re-queue it to be sent on the next successfully-opened TCP connection.
PakBus
This port uses the PakBus protocol.
MODBUS/TCP gateway
The device will listen for incoming Modbus/TCP connections from a remote client. The port
number of the listening connection is specified in the RS-232 Service Port setting. The device
will convert incoming Modbus/TCP frames to Modbus/RTU and forward them to the RS-232
port. The device will wait for a response from the Modbus/RTU device and forward the
response back to the remote Modbus/TCP client over the established TCP connection.
Disabled
This port will not be used.
B.3.2 RS-232 Service Port
This setting is used when the RS-232 Configuration is set to Serial Server or MODBUS/TCP
gateway. To communicate with a TCP/IP server, the client application must open a socket to that
server. The socket of a specific server is uniquely identified by an IP address of the host where the
server is running and a port number associated with the server application on that host. This
entry is where the port number of the server is set. Ensure that the client application is set to use
the same port number as configured here. Most MODBUS/TCP applications use port 502 (range 1
to 65535).
NL241 Wireless Network Link Interface
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