Implement fetch/write on s7 315-2 PN/DP

The 315-2 PN/DP has built in ethernetinterface. Siemens do not provide fetch/write functionality as if you use CP343-1 or CP443-1.

Siemens has already implemented this:
https://support.automation.siemens.com/WW/skm/frameset.asp?url=%2FWW%2Fllisapi%2Edll%2F23592043%3Ffunc%3Dll%26objId%3D23592043%26objaction%3Dcsopen%26siteid%3Dcseus%26aktprim%3D0%26skm%3D1%26lang%3Den&Query=communication+315%2D2&SearchArea=alle&id=23592043&F11Marker=false&siteid=cseus&query2=&modelled=&lang=en

But they charge you money for it.. *******s!

Has anyone out there already implemented this or any other tcp native protocol for reading/writing from/to the memory using s´7 315-2 PN/DP?

My task is to read/write some bytes in the send them to a PC.

Is there any particular reason to that you want to use Fetch/Write ?
You say that you want to send data to the PC (that is how I interpret your text). In that case Fetch/Write is the wrong choise. Fetch/Write means that the S7 PLC will respond to incoming datatransfer commands. The S7 PLC cannot itself initiate anything.

I can help you a bit, but I need to know the following:

What is it that you want to achieve functionally ?

What PC application (or kind of application) will communicate with the S7 PLC ?