I am not familiar with simulink specifically but you can implement basically any protocol using LabVIEW's TCP/IP primatives. Whether the protocol used by simulink is documeted or not is another matter. You need to know the port number, IP addresses and application protocol used in order to do this. Whether anyone has done this already or if it is available for public use, I can't say.
Mark Yedinak Certified LabVIEW Architect LabVIEW Champion
"Does anyone know where the love of God goes when the waves turn the minutes to hours?" Wreck of the Edmund Fitzgerald - Gordon Lightfoot