Port redirection
For some applications, port redirections need to be configured to forward data packages from the TCP listening port to another FP‑I4C interface.
General principle
An open TCP listening port is redirected to a serial COM interface (blue arrows). This allows external clients to communicate via TCP with a device connected to the COM interface.
Example
Three TCP listening ports are opened on the FP‑I4C unit (9094, 502, and 9095) and redirected to two serial COM interfaces connected to an FP0H PLC:
Port 9094 handles requests from the PLC programming software Control FPWIN Pro7 to the PLC. The port is redirected to the USB interface.
Port 502 is used as a Modbus TCP gateway to handle data requests from a Modbus TCP client.
Port 9095 is used as a MEWTOCOL server to handle MEWTOCOL data requests from a SCADA system.
In addition, a Web server (HMI Runtime) is installed in the FP‑I4C unit to show PLC data on an HTML page. The Web server connects to the PLC using the localhost IP address 127.0.0.1. In the example, HMI Runtime collects data from the PLC via MEWTOCOL and port 9095.
The data from port 502 and 9095 is redirected to the RS485/RS232 interface and then transmitted to the PLC FP0H. The SCADA system with polling rates in the millisecond range causes high loads on the serial interface. It is therefore advisable to use a different serial interface (in this example USB) for remote programming of the PLC.
Configure a port redirection
With the PLC connection wizard, you can set a port redirection very quickly. Alternatively, you can also configure the redirection manually.
In the following example, the TOOL or COM port of the FP0R PLC is connected to COM1 RS232 of the FP‑I4C unit. A PC is connected to one of the Ethernet interfaces of the unit. To establish a connection between the PC and the PLC via the FP‑I4C unit, open port 9094 for COM1 RS232, and make the communication settings.
Using the wizard
Go to COM Interface and select Start wizard to start the PLC connection wizard.
Select Simple mode and Continue.
Select the interface used to communicate with the PLC (COM1 RS232) and then Continue.
Set baud rate and parity (or IP address and port if the interface is COM4 Ethernet).
Enter the TCP listening port number (9094).
Select Finish and save your configuration.
Manual configuration
Go to COM Interface and enable the interface COM1 RS232 to communicate with the PLC.
Make the desired communication settings.
Go to Service control interface and select RS232 as COM interface to control device (PLC) and the station number.
Go to and select Add new.
Specify the TCP listening port number 9094 and the COM interface RS232 to which the data packets should be forwarded, and make all other desired communication settings.
Save your configuration.