Usage

Setup

Needed Variables

UDPCommMgr_typ commMgr;
STRING[255] sendBuffer;
STRING[255] recvBuffer;

Initialization

commMgr.IN.PAR.pSendData = &sendBuffer;
commMgr.IN.PAR.pReceiveData = &recvBuffer;
commMgr.IN.PAR.MaxReceiveLength = sizeof(recvBuffer);

strcpy(commMgr.IN.CFG.LocalInterface.IPAddress, "127.0.0.1");
commMgr.IN.CFG.LocalInterface.Port = 5000;

strcpy(commMgr.IN.CFG.RemoteInterface.IPAddress, "127.0.0.1");
commMgr.IN.CFG.RemoteInterface.Port = 5001;

commMgr.IN.CMD.Enable = TRUE;

Setting commMgr.IN.CMD.Enable to TRUE is required to open the socket; the communication manager stays idle until this is set.

Sending Data

Set commMgr.IN.PAR.SendLength to the number of bytes to send, then set commMgr.IN.CMD.Send to trigger the send (or hold it TRUE continuously if AllowContinuousSend is set). commMgr.OUT.STAT.DataSent goes TRUE once the datagram has been sent, and commMgr.OUT.STAT.SentDataLength reports how many bytes went out.

commMgr.IN.PAR.SendLength = strlen(sendBuffer);
commMgr.IN.CMD.Send = TRUE;

// Call UDPCommFn_Cyclic(&commMgr) every scan while commMgr.IN.CMD.Enable is TRUE

if (commMgr.OUT.STAT.DataSent) {
	commMgr.IN.CMD.Send = FALSE;
}

Receiving Data

While the communication manager is enabled, incoming datagrams are copied into commMgr.IN.PAR.pReceiveData automatically. commMgr.OUT.STAT.NewDataAvailable goes TRUE when a datagram has arrived, with commMgr.OUT.STAT.ReceivedDataLength and commMgr.OUT.STAT.ReceivedFromInterface describing it. Set commMgr.IN.CMD.AcknowledgeData to clear the flag and resume listening for the next datagram (or set AllowContinuousReceive to clear it automatically).

if (commMgr.OUT.STAT.NewDataAvailable) {
	// recvBuffer now holds commMgr.OUT.STAT.ReceivedDataLength bytes
	commMgr.IN.CMD.AcknowledgeData = TRUE;
}

Handling Errors

If commMgr.OUT.STAT.Error is set (for example, due to an invalid configuration), the communication manager parks in an error state and will not reopen the socket on its own. Recover by cycling commMgr.IN.CMD.Enable to FALSE and back to TRUE. See Structures and Enums for the list of error codes reported in commMgr.OUT.STAT.ErrorID.