Application Research of Priority Scheduling in Switched Industrial Ethernet

To overcome the drawback that the switched Ethernet does not guarantee the timely delivery of real-time data in industrial communication,IEEE802.1p queuing feature was introduced into both Ethernet switches and communication nodes to give real-time data the priority to access network. In addition,real-time priority field was introduced into real-time data frames to differentiate their emergency degree,and non-preemptive fixed priority scheduling method was applied to improve the end-to-end delay of real-time data. By combining worst-case response time analysis method and network calculus approach,a hybrid method to optimize upper bound of end-to-end delay of real-time data was also proposed. A comparison study showed the advantage of the method.