Traditional architectures of factory automation networks possess some shortcomings, such as needing gateways to transform communication data, using multiple different kinds of networks, needing higher maintenance cost, etc. To remedy the shortcomings, a novel Ethernet-based equipment integration framework is proposed in this paper. The proposed framework is qualified to be an equipment (synchronous) control network for the factory automation networking. Also, it conforms to the technical trend of replacing traditional industrial networks with Ethernet. Many technologies, including the master/slave model, Ethernet Switch, realtime operating system kernel, real-time transmission control protocol/Internet protocol application programming interface, and object request broker (ORB), are exploited to develop the framework. Simulation and experimental results for a laboratory-scale factory indicate that the proposed framework can perform well in real-time data transmission, that is, accomplishing the synchronous communication over 10 slave nodes within 1.4 ms. Additionally, the equipment integration framework can be easily integrated with the automation systems in the information-management layer through ORB. Worst-case performance evaluations and timing-parameter setting formulas for the proposed framework are also provided. The work presented here is believed to be a good paradigm for developing Ethernet-based factory automation networks. (C) 2004 Elsevier Ltd. All rights reserved.
