Function Block Application in ARM-based Field Intelligent Instruments

The design and implementation of function block application (FBA) in intelligent instruments is the core to the implementation of control function from intelligent field instruments. Function blocks represent the basic automatic function implemented by function block application. In this paper, the features of function block in intelligent field instruments based on ARM processor are analyzed, method and scheme for design and implementation of function block application in ARM-based intelligent instrument are proposed, which are based on function block parameters-type description, data partition and storing structure in intelligent instruments. 4 data-storing segments are allocated in static memory of intelligent instrument, which are instruction segment, input segment, output segment and contained parameters segment. Static pointers to respective data-storing segments are created, with which any parameters information used in function block application can be found quickly combined with the data and information stored in instruction segment, by which the connection and communication between function blocks are implemented. A implementation method for the operation mode of multi FBA (MFBA) based on map of data segment and memory allocation in intelligent instruments to virtual registers is proposed. The structure and implementation in C++ for the instruction code in instruction segment are also presented. The experimental and operational results show the design and implementation scheme for function block application in intelligent instruments with ARM kernel are scientific and reasonable, stable and efficient in operation.