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

2016 ◽  
Vol 64 (1) ◽  
pp. 161-170 ◽  
Author(s):  
A. Milik ◽  
M. Chmiel ◽  
E. Hrynkiewicz
Keyword(s):  
Program Analysis ◽  
Formal Method ◽  
Control Program ◽  
Program Execution ◽  
Task Partitioning ◽  
Selective Control ◽  
Conditional Control ◽  
Changes Detection ◽  
Plc Program ◽  
Selective Program

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.

scholarly journals Reconfigurable Logic Controller—Direct FPGA Synthesis Approach

2021 ◽  
Vol 11 (18) ◽  
pp. 8515
Author(s):  
Adam Milik ◽  
Marcin Kubica ◽  
Dariusz Kania
Keyword(s):  
Response Time ◽  
Program Implementation ◽  
High Performance ◽  
Formal Method ◽  
Control Program ◽  
Graph Representation ◽  
Program Execution ◽  
Intermediate Form ◽  
Automation Systems ◽  
Programmable Devices

Programmable logic controllers are commonly used in automation systems. Continuously growing demands result in the growth of control program complexity. The classic approach, based on programmatic serial-cyclic execution, results in an unacceptable extension of response time. To overcome long response time massive parallel program execution is proposed. It utilize direct in hardware program implementation in field programmable devices. The paper brings a formal method of representing control programs using flow graphs and enabling single cycle computations. The developed method accepts ladder diagrams (LD) and sequential function charts (SFC), according to IEC61131-3 standard requirements. It is capable of handling logic and arithmetic computations, enabling its hardware mapping. The intermediate form is optimized using flow graph representation and BDDs for analyzing logic dependencies. The BDD representation of logic dependencies enables direct mapping to lookup tables of a selected FPGA family. All the above steps deliver high-performance and direct hardware implementation of the control program given by standard languages. The controller response time is short, predictable, and independent from logic conditions during program execution.

Design of Analyzers for Selective Program Analysis

1981 ◽  
Vol SE-7 (1) ◽  
pp. 39-51 ◽  
Author(s):  
J. Arthur ◽  
J. Ramanathan
Keyword(s):  
Program Analysis ◽  
Selective Program

Greenhouse Moisture and Temperature Fuzzy Control System and PLC Program Design

2014 ◽  
Vol 721 ◽  
pp. 265-268
Author(s):  
Mao Qi Huang ◽  
Jian Hong Ke ◽  
Xiao Long Wu
Keyword(s):  
Complex System ◽  
Control System ◽  
Fuzzy Control ◽  
Control Program ◽  
Control Effect ◽  
Math Model ◽  
Fuzzy Control System ◽  
Temperature Controller ◽  
Plc Program ◽  
And Control

Greenhouse environment system is an often nonlinear, change and inertia complex system. It is very hard to build math model and control. Since moisture and temperature have a influence to crops grow, we select them to build the manner of control system, applying fuzzy control system to design moisture and temperature controller, and to write fuzzy control program based PLC, then we should observe the factual control effect. The result of system running show: when temperature is set to 25oC and moisture is 80%RH, the process of control is stable and the system is very stable, it can meet the greenhouse requirement.

scholarly journals Virtual commissioning of automated manufacturing systems — Quality-handling station case study

2021 ◽  
Vol 343 ◽  
pp. 04002
Author(s):  
Richard Skýpala ◽  
Roman Ružarovský
Keyword(s):  
Production System ◽  
Manufacturing Systems ◽  
Control Program ◽  
Simulation Software ◽  
Second Phase ◽  
Automated Manufacturing Systems ◽  
Digital Twin ◽  
Virtual Commissioning ◽  
Systems Quality ◽  
Plc Program

The aim of the contribution is to create an event-controlled simulation of an automated production system using selected simulation software according to analyses and creation PLC control program compatible with human-machine control interface (HMI) visualization. The programmer can test the control program without the need for additional hardware on a virtual model of the machine. This method is called as a Virtual Commissioning method. The question is whether these new digital technologies are beneficial in the development process of new machines. The theoretical part of the contribution deals with the evaluation of the current state of knowledge in the field of virtual commissioning systems from the perspective of the Industry 4.0 concept and the use of principles taken from the technology of digital twins for analysing the possibilities of productive support of simulation, programming and visualization of control. For the Virtual Commissioning of the Quality-handling station from a flexible production system. It was chosen Tecnomatix Process simulating software for the developing of the Digital Twin of the station that is suitable for the connection of the logical behaviour inputs and outputs of the Digital Twin to the PLCSIM emulator. The main goal is to create a functional PLC program, so that in the second phase the process of virtual commissioning can be tested by the Software-the-Loop method. The preparation of the simulation model consists in a sample of the control station model of the production system, the process of creating kinematic bonds, behaviour model, creating control signals in the Tecnomatix Process Simulate program. Programming procedure and acquaintance with control means in the Simatic Manager program, selection of communication interface and creation of control visualization. In the final work, validation is performed and evaluation supports the objectives and the results confirmed the benefits of the Virtual Commissioning tool.

scholarly journals Behaviour Analysis and Safety Conditions: a Case Study in CML

1997 ◽  
Vol 26 (528) ◽  
Author(s):  
Hanne Riis Nielson ◽  
Torben Amtoft ◽  
Flemming Nielson
Keyword(s):  
Embedded System ◽  
Programming Language ◽  
Program Analysis ◽  
Process Algebra ◽  
Control Program ◽  
Inference Algorithm ◽  
Behaviour Analysis ◽  
Automatic Inference ◽  
Production Cell

We describe a case study where novel program analysis technology has been used to pinpoint a subtle bug in a formally developed control program for an embedded system. The main technology amounts to first defining a process algebra (called behaviours) suited to the programming language used (in our case CML) and secondly to devise an annotated type and effect system for extracting behaviours from programs in a such a manner that an automatic inference algorithm can be developed. The case study is a control program developed for the "Karlsruhe Production Cell" and our analysis of the behaviours shows that one of the safety conditions fails to hold.

Generalizing direct load control program analysis: implementation of the duty cycle approach

1989 ◽  
Vol 4 (1) ◽  
pp. 293-299 ◽  
Author(s):  
N.E. Ryan ◽  
J.T. Powers ◽  
S.D. Braithwait ◽  
B.A. Smith
Keyword(s):  
Duty Cycle ◽  
Program Analysis ◽  
Control Program ◽  
Load Control ◽  
Direct Load Control

Generalizing Direct Load Control Program Analysis: Implementation of the Duty Cycle Approach

1989 ◽  
Vol 9 (2) ◽  
pp. 62-62
Author(s):  
Nancy E. Ryan ◽  
John T. Powers ◽  
Bruce A. Smith ◽  
Steven D. Braithwait
Keyword(s):  
Duty Cycle ◽  
Program Analysis ◽  
Control Program ◽  
Load Control ◽  
Direct Load Control

Selective Control Program for the Pear Pest Complex in Southern Oregon

1986 ◽  
Vol 79 (1) ◽  
pp. 250-257 ◽  
Author(s):  
P. H. Westigard ◽  
L. J. Gut ◽  
W. J. Liss
Keyword(s):  
Control Program ◽  
Selective Control
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