Communication is one of the important functions in the middle layer of the 3-layered typical architecture of open controllers. Most of the realized communication is based on the OSI Reference Model which may affect system performance if the communication behaves in local ranges. In order to improve system performance and to keep the reliability of communication, the hierarchical object-oriented Petri net (HOONet) is modified and time information is attached to it. Then the simplified synchronous and asynchronous communication model is completed based on the modified HOONet.