數據通訊是控制系統的關鍵技術之一。本文闡述了西門子S7 系列PLC 數據通訊在某大型水壓機控制系統中的實現，介紹了3 種常用的通訊網絡。針對該水壓機控制系統對輸入信號需做出快速實時響應的特點，合理地選用了PROFIBUS-DP 和MPI 2 種網絡實現了不同PLC 間的數據通訊，并給出了部分通訊程序。實踐表明該系統的數據通訊功能運行情況良好，既滿足了實時快速性要求，又具備較高的通訊效率。
關鍵詞：PLC；數據通訊；實現；PROFIBUS-DP；MPI;
Abstract: Data communication is the one of the key factors in control system. The realization of Data communication between Simatic S7 PLC in the control system of a large hydraulic press machine is interpreted in the thesis. Three kinds of popular communication network are introduced. Aiming at the characteristic of responding to input signal promptly, PROFIBUS-DP and MPI have been appropriately selected to carry out the data communication between different PLC, and part of the program is interpreted. The system functions well and reliable. The speedy and Real-time requests have been satisfied and the system is efficient.
Key words: PLC; data communication; realization; PROFIBUS-DP; MPI;