UDP: Example for Server and Client

Create a "Standard project" and select CODESYS Control Win V3 as the device.
Define the target system by means of the Network scan.

Open the Library Manager and add the Netzwork library.

Add a global variable list to the project and define the following variables:

{attribute 'qualified_only'}
VAR_GLOBAL
    sIpAddr    :    NBS.IP_ADDR := (sAddr := '192.168.99.74'); // Change to own IP-Address
	// !!!  Make sure that the firewall does not block these ports !!! 
    uiPort     :    UINT := 8181; // Port for the sender => receiver will set to uiPort + 1
END_VAR

Add a POU to the project and name is UdpClient.

Adapt the POU UdpClient as follows:

Declaration

VAR
    fbPeerClient    :    NBS.UDP_Peer;
    fbReceive       :    NBS.UDP_Receive;
    sRcvMsg         :    STRING;
END_VAR

Implementation

fbPeerClient(xEnable := TRUE, ipAddr:= GVL.stIpAddr, uiPort:= GVL.uiPort + 1);

fbReceive(xEnable := (fbPeerClient.hPeer <> CAA.gc_hINVALID), 
            hPeer := fbPeerClient.hPeer, 
            szSize := SIZEOF(sRcvMsg), 
            pData := ADR(sRcvMsg));

Adapt the POU PLC_PRG as follows:

Deklaration

VAR
	fbPeerServer    :    NBS.UDP_Peer;
    fbSend          :    NBS.UDP_Send;
    xSend           :    BOOL;
    sSendMsg        :    STRING := 'Hello World';
END_VAR

Implementierung

UdpClient();

fbPeerServer(xEnable := TRUE, ipAddr := GVL.stIpAddr, uiPort := GVL.uiPort);

IF fbPeerServer.hPeer <> CAA.gc_hINVALID THEN
    fbSend(xExecute := xSend, 
            hPeer := fbPeerServer.hPeer,
            ipAddr := GVL.stIpAddr, 
            uiPort := GVL.uiPort + 1, 
            szSize := SIZEOF(sSendMsg), 
            pData := ADR(sSendMsg));
END_IF

IF xSend THEN
    xSend := FALSE;
END_IF

Start the project and set the xSend variable to TRUE.

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UDP: Example for Server and Client