By Topic

An extraction method of control flow from ladder diagram by judgement of transfer frequency

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

3 Author(s)
Shoji, N. ; Dept. of Inf. Syst. Eng., Osaka Univ., Japan ; Ikkai, Y. ; Komoda, N.

In sequential controllers of plants, the ladder diagram is one of the major programming languages. However, it is difficult to understand its control sequences and to maintain them because ladder diagrams do not clearly represent the sequence of plant behavior. The Sequential Function Chart (SFC), which is based on the Petri net, has recently spread as a powerful graphical description of sequential logic. SFC can represent clearly the sequence of control programs. Therefore, a method to translate ladder diagrams to SFC is required. A control sequence extraction method is proposed. In this method, a tentative SFC is created by searching all possible states by using transitions in the ladder diagram. However, the tentative SFC description is complicated because of the existence of non-order control, which does not depend on a fixed sequence, for example manual control. Therefore, the sequential flow of plant behavior in the tentative SFC is extracted according to the difference of transfer frequency between order control and non-order control. Through an application of the proposed method to a practical plant model, it is confirmed that the adequate sequence which represents the original plant behaviour is extracted from the ladder diagram

Published in:

Emerging Technologies and Factory Automation, 1999. Proceedings. ETFA '99. 1999 7th IEEE International Conference on  (Volume:2 )

Date of Conference: