Hello,

generally I recommend check on web topics about TCP (example link): TCP Wiki

In simply explained, in your projects you need define 'path' with IPs and Ports of partners that data can reach partner, this is role of TCP - delivery of data to defined partner/destination and also safely. Of course you need save your data to some memory after receive to look and manipulate, to this you need set block of memory, DB or structure. In your code you need then execute needed instructions with SEND/RECEIVE, maybe also coordinate both devices if you need. Generally same structure in case of send data from one device to another is expect.

Update: simply you only execute your needed instructions and check statuses - bit memory or word to know how process going. How data running to one partner to another is role of HW, you need only check mentioned recommendations basically.