초록 ▼

A distributed processing unit (DPU) or drop which performs process control and data acquisition functions in a distributed processing control system having a data highway linking a plurality of such units. A DPU functional processor accesses the local process I/O interface thereby continually receiv

A distributed processing unit (DPU) or drop which performs process control and data acquisition functions in a distributed processing control system having a data highway linking a plurality of such units. A DPU functional processor accesses the local process I/O interface thereby continually receiving plant information for storage in digital form and subsequent use in the functional processor or for transmission along the data highway. DPU control programs use process values in a transparent fashion, that is without regard to whether these values were obtained through local process I/O interface or via the data highway. The DPU software structure is made up of execution software and support software. The execution software is a collection of data acquisition and process control programs which are developed at an engineer\s console drop using a DPU programming language which operates in text and CRT graphic display modes, the latter programming modes allowing system documentation via hard copy graphic display printout. These programs are initiated, performed consecutively, and repeated at specified intervals. The support software initiates process loop execution. Control programs which have been presented to the DPU as representations of ladder diagrams for sequential control or process flow diagrams for continuous process control are executed in the DPU functional processor to achieve the required process control operation.

대표청구항 ▼

Method of developing a process control loop program for execution in a digital processing unit (DPU) to control a process, said method comprising the steps of: (a) storing a graphics program representation of a predetermined graphical grid pattern of an unconfigured process control loop in a memory,

Method of developing a process control loop program for execution in a digital processing unit (DPU) to control a process, said method comprising the steps of: (a) storing a graphics program representation of a predetermined graphical grid pattern of an unconfigured process control loop in a memory, said grid pattern having a predetermined number of input and output process control loop entries with predefined locations therein; (b) causing said graphics program to be executed by a controller to display said grid pattern on a visual display device; (c) selecting at least one algorithm for said process control loop program from a library of algorithms stored in a memory; (d) causing a predefined outlined region to appear in the displayed grid pattern at a specified location for each selected algorithm; (e) setting parameters associated with each selected algorithm; (f) selecting at least one input entry from said predetermined number thereof for said process control loop program and assigning a predefined input variable of said process control loop to each selected input entry; (g) causing each said input entry selection and corresponding assignment to appear in the displayed grid pattern at its predefined location; (h) selecting at least one output entry from said predetermined number thereof for said process control loop program and assigning a predefined output variable of said process control loop to each selected output entry; (i) causing each said output entry selection and corresponding assignement to appear in the displayed grid pattern at its predefined location; (j) causing graphical line interconnections to be drawn in the displayed grid pattern between the selected algorithm region locations and the selected input and output entries to configure a block diagram schematic of the desired process control loop; (k) storing in memory information of said process control loop generated during the graphical configuration thereof in accordance with the above steps (c) through (j); and (l) converting the stored information of the configured process control loop into instructional program code for execution in said DPU, whereby as the graphical display of the process control loop is completed on the visual display device, the process control loop program may be concomitantly completed for use by said DPU.