Research On The Key Technology Of PROFINET-PROFIBUS PA Gateway

It is a revolutionary breakthrough of the transformation from analog signal to digital signal in industrial networks. Intelligence instrument and fieldbus control system(FCS) were widely used in industry. In order to realize the integration of control systems and enterprise management information networks, Ethernet technology has become welcome by the industry for its open infrastructure and mature technology. Real-time industrial Ethernet achieved, so it become true of depth integration between control network and enterprise IT networks, an opened and interconnected Infranet / Intranet / Internet network infrastructure formed in the industry.Industrial Ethernet is widely used, research on it is more than the bus system, but its coexistence with the fieldbus situation will continuous for long time, so the integration program of the two systems have been proposed. This thesis took the program of industrial heterogeneous network integration as the key issue, to achieve the integration of fieldbus and Industrial Ethernet. A PROFINET-PROFIBUS PA gateway was taken as an example, some key technologies were studied as follows.(1) This two industrial network protocol structures were analyzed, and the differences between the two networks(eg. physical layer, transmission rates) were taken into account. Then a proxy based system integration model was designed. Taking into account the characteristics of PROFIBUS PA we selected the system mapping model of modular mapping, fieldbus intelligent instruments mapped as a PROFINET IO device modules, IO data cache to the corresponding slot /subslot model, the mapping between the two protocols corresponding services was defined.(2) The hardware of gateway with ERTEC 200 Ethernet communication chip and FBC0409 communication chip was designed and implemented after we studied the physical layer features of PROFINET IO and PROFIBUS PA. Affter that, a PROFINET IO device protocol software was transplanted the board, a simplified PROFIBUS Class1 master with the ability to read and write PROFIBUS PA slaves cyclically and acyclically was designed and implemented. The software to mapping the two protocols and profiles was implemented on user layer.(3) A gateway GSDML file generating tool used to transform PROFIBUS PA slaves to PROFINET IO moudles was designed and implemented based on the specification of GSDML and GSD files. This tool could generate GSDML files of gateway according the applications. It is convenient for industry users.A set of test rig was set up with a Siemens S7-300 PLC as IO controller and two Siemens TH400 temperature transmitters use to evaluate the gateway.PROFIBUS PA and PROFINET network achieved the interoperability in experimental system, IO controller could read and write PROFIBUS PA devices, input and output time delay could be adjusted according to PROFIBUS PA network equipment.The experimental results demonstrate the feasibility of the design of the gateway, the gateway achieved basic communication functions, all of these equipments integrated in a whole interoperable network. The gateway's time delay can be adjusted to a certain extent, to meet the engineering applications for process control PROFIBUS PA feildbus system.