On the systematic method of conditional control program execution by a PLC

Abstract

Abstract. The paper presents an original idea of the selective control program execution that allows significant response time reduction. The exhaustive analysis of the PLC program performance is given. An analytic approach explains the idea of the selective control program evaluation and gives the requirements for its feasibility. There is presented a systematic and formal method of program analysis based on a data flow graph approach. The method generates acyclic graph from the control program that is subject of optimization, variable allocation and instruction generation. The graph approach allows determining variables dependencies and task partitioning required by selective program execution. The method utilize the hardware supported variable changes detection. It is transparent for system operation and enables evaluation of blocks that require update.

Bulletin of the Polish Academy of Sciences: Technical Sciences

“…One of many possible solutions is the use of fuzzy logic as a tool for describing inaccurate phenomena. The above statement is confirmed in studies such as [1] and [2][3][4][5]. The theory [6] formulated by Zadeh in mid-sixties has become an alternative to existing mathematical models.…”

“…Similarly, the LOM (last of maxima) method is a method in which the value of defuzzification equals the last element of the kernel. In the experiment, two OFNs, the first H = [4,6,8,14] and the second oppositely directed Z = [14,8,6,4] were used. The graphical interpretation of the numbers H and Z is demonstrated in the figure below.…”

A system for monitoring and controlling a thermal energy store and an energy capture system

“…It relies on computerized control and measurement systems based on programmable logic controllers (PLC). A PLC has been analysed extensively by Milik et al [18] who described the programming operations performed by PLCs, time dependencies and responses to real-time events. Data control and acquisition systems operate autonomously in a supervisory control and data acquisition system (SCADA).…”