Hello everyone. New to this forum, loving using Qt.

My question:
I am trying to implement Modbus protocol using Qt on TCP. Looking at various articles, a lot of them are obviously for serial connection, and a lot more include precompiled libraries, and others are for linux (I'm using Windows), with the result that I'm not making progress.

However, from what I have seen, a socket connection gets made, with a few options set, using structures to store the ip address, port, file descriptor, etc which then uses the memset function to clear it. Then there is a command setsockopt to set options of the socket like TCP_NODELAY, IP_TOS. Do I really need all this?

In Qt, it "appears" as easy as

Qt Code: 
  1. tcpSocket = new QTcpSocket(this);
  2. tcpSocket->connectToHost("193.1.1.14",502);
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Now I say appear, because I'm sure it isn't, however, I do manage to connect by viewing the socket state, and it returns connection established.

The next stage again appears that I need to write to the socket, and then read something back. Now this is where I am stuck, and would appreciate help. I don't mind the hard work, just some guidance please.