Sample06: "Echo" client/server with TLS (basic modules)

The following sample is essentially based on Sample01 and shows an exemplary implementation of an "Echo" client/server system. The client sends a test string to the server at certain intervals (e.g. every second). The remote server sends this string back to the client.

In contrast to Sample01, the communication connection in this sample is secured via TLS with client/server certificates. The certificates are not part of the sample and must be created by the user.

In essence, this sample thus illustrates the use of the function blocks FB_TlsSocketConnect, FB_TlsSocketCreate, FB_TlsSocketListen, FB_TlsSocketAddCa, FB_TlsSocketAddCrl, and FB_TlsSocketSetCert. These were integrated accordingly into the state machine of the client and server sample from Sample01.