The Development Of Function Block In The Foundation Fieldbus Pressure Transmitter

The Foundation Fieldbus (FF) is the most advanced fieldbus in theprocess automation area.The purpose of this thesis is to study anddevelop the Function Block (FB) in the FF Pressure Transmitter.It will behelpful to reduce the gap of the instrumentation products between theinternational leaders and the instruments manufacturers in our country.Firstly, the FB related issues were analyzed in detail.Then the AI (AnalogInput) FB was developed under an OEM development environmentselected.The AI FB software is comprised of four modules: the inputparameter module, the working modes module, the block algorithmmodule, and the alarm management module.The development wasproved to be successful by a laboratory test.Finally, the execution andscheduling of the FB was studied and analyzed in detail, and theexperiments for evaluating the fieldbus communication performance wereconducted in an FF control system.The conclusion is that differentconfigurations for one application will influence the communicationperformance: the more the communication times, the larger the trafficload on the fieldbus, however the period jitter of communication is small.This is practical for the application configuration of the FF controlsystem.