Hello everyone,

so I am trying to implement a UDP server that will wait for a message from a client and then send data to that client.
The problem is, I cannot find a way to get the port number of the UDP client that is sending a message to me.
I have created the socket like this:

        thesocket :=SysSockCreate(  iAddressFamily  := SOCKET_AF_INET,
                                    diType          := SOCKET_DGRAM,        (* For UDP*)
                                    diProtocol      := SOCKET_IPPROTO_UDP,  //or SOCKET_IPPROTO_IP ?
                                    pResult         := ADR(CreateErrorCode));

bound like this:

m_bound := SysSockBind(         hSocket         := thesocket,
                                pSockAddr       := ADR(MySocket),   
                                diSockAddrSize  := SIZEOF(MySocket));       

Now I imagine I receive a message here:

m_receivedBytes := SysSockRecvFromUdp(  hSocketUDP  := thesocket, 
                                        pbyData     := m_RecvBufferAddr, 
                                        diDataSize  := m_RecvBufferSize, 
                                        pReply      := ADR(m_clientInfo), 
                                        pResult     := ADR(m_received));

now m_clientInfo is of type UDP_REPLY which contains the IP address of the client. When I want to respond via SysSockSendToUdp I need to specify the destination port (of course).
In the documentation of sysScoket ( https://help.codesys.com/webapp/idx-SysSocket%20Implementation-lib;product=SysSocket%20Implementation;version=3.5.15.0 ) I could not find a receive method that would work on my UDP socket and give me a socketaddr type.

I hope someone can help me.

Best regards

Did you had a look at CAA Net Base Services ?
There's some UDP server that may help. Also have a look in codesys store for exemple project.

https://help.codesys.com/webapp/idx-CAA_NetBaseServices-lib;product=CAA_NetBaseServices;version=3.5.9.50

Hi dFx, thank you very much for your reply.
Yes, in the end I solved it with the NBS library. Their UDP.Receiver has a structure that contains the remote IP and port - that way I could then establish a two way communication.