This port was based on the original STR71X port of FreeModbus. It adds PPP support to lwIP and includes an advanced serial driver which uses the FIFOs of the UART. It supports PPP connection up to 115200baud and include a working Modbus/TCP example application. The files for this port can be found in demo/STR71XTCP.
The next figure shows an example of the debug console from the embedded target. First a PPP connection was established with a Linux host system with a Null-Modem cable. The a new Modbus/TCP client connected with IP address 10.0.10.1 and sent two Modbus commands. After that the client has disconnected.