| The 2-layer master/slave control system is widely used in industry for its simple architecture,where there are numerous slave nodes and distributed field-devices with real-time communication.As industry autoimmunization steps forward,higher demands are proposed for the network flexibility,and for the reliable real-time communication.Based on the studies in industrial Ethemet protocols,we proposed a new Ethernet protocol,in which we introduced the idea of lumped-frame.In this protocol,the conventional Ethernet communication model is improved.The new protocol overcomes most of the shortcomings of conventional Ethernet,such as complex network-addressing,big frame overhead and communication uncertainty.The new protocol performs well in the 2-layer master/slave control systems.It encapsulates all the slaves' data into a lumped frame.This results in high application data ratio and easy network-addressing,which can be done in one communication period.With the one-way ring topology and the delay-transmit-treat mechanism,we can get very high speed in the network transmission.With the SOPC technology,we designed the master and slave nodes respectively and developed an experiment platform for the 2-layer master/slave control systems. The experiments and analysis indicated that the system is quite flexible in reliable real-time communication.The new protocol can be realized easily for its simple framework.It is an advanced work and quite worthful for practical use.For fault treatment and maintenance of network,we designed a protocol analyzer to analyze the commands and data transmitted in the network. |
