Research And Implementation Of Key Technology Of Modbus TCP Adapting To Time Sensitive Network

With the development of the Industrial Internet,the real-time requirements of industrial networks for industrial production are more and more strict.Modbus TCP industrial protocol has been widely used in industrial networks because of its advantages such as simple protocol,open source and easy integration.However,its further development is hindered by the lack of real-time capability.The emergence of Time-Sensitive Networking(TSN)has pointed out a new direction for industrial development,which can provide services with low latency,low jitter and high-reliability.In order to improve the real-time performance of Modbus TCP network,the thesis proposes a Modbus TCP adaptation timesensitive system architecture,classifies different Modbus TCP data types to adapt to the Time Sensitive Network and ensures Modbus TCP data through the scheduling mechanism of the Time Sensitive Network.Modbus TCP data flow has low latency and low jitter,which improves the real-time performance of Modbus TCP network.The main research work is as follows:1.This thesis analyzes the research status of Modbus TCP and TSN,summarizes the transmission mechanism and application requirements of Modbus TCP,puts forward the research and implementation method of real-time guarantee mechanism of TSN,and the problems faced by Modbus TCP adapting to TSN.2.According to the network structure and data transmission characteristics of Modbus TCP and TSN,this thesis designs a network architecture that Modbus TCP adapting to TSN.Through the classification of the different data types in the Modbus TCP network,combined with the 8 data types in the TSN,the adaptation rules of the Modbus TCP data stream mapping to the TSN data stream are defined.3.In the Modbus TCP adaptating to TSN,since the gated scheduling mechanism increases the delay of aperiodic adaptive flow.This thesis proposes a grouping transmission optimization scheme,which takes the delay of the aperiodic flow as a constraint,rearrange the transmission sequence of the periodic adaptation stream and generate a new gated scheduling list.In the scheduling period,the delay of the aperiodic adaptor flow is reduced by reducing the time that the periodic data flow continues to occupy the port and the length of the aperiodic waiting time slot.4.This thesis builds a test and verification platform for Modbus TCP adaptating to TSN,the platform includes Modbus TCP client and server,protocol tester,adaptation equipment and TSN switch.The test results show that after Modbus TCP is adapted to the TSN,the real-time performance of Modbus TCP data flow is guaranteed,the network delay is less than 1ms and there is no packet loss.At the same time,the grouping transmission scheduling strategy can effectively reduce the delay of aperiodic adaptive flow by 9.7%while ensuring the delay of periodic adaptive flow.