i.mx rt 1050 evkb lwip tcp client

[albertobeghetto]

Hi,

i'm trying to develop a tcp client to make a modbus client. My idea is to start from a workin tcp client, edit layer 2 writing modbus protocol that i just develop in serial rtu mode.

Navigating in example projects (sdk 2.5.1) i can't find any tcp client, only servers. My knowledge for lwip is very low and i'm not able to edit server application layer to make a client. Client request implementing pool table, pool time, opening connections, manage lost connections, etc, i don't how to manage interface with other layer in lwip.

There is some giudelines to do it?

Thanks in advice

Alberto

[danielchen]

Hi Alberto:

TCP client is an application that actively connect to remote applications in order to obtain a service from the remote application. The remote application is the server.

Please refer to the lwip_tcpecho_freertos demo. The application sends back the received TCP packets from the PC. The simple transaction between an echo client and an echo server is as below.

Regards

Daniel