Study on execution time of ladder diagram in programmable controller

In this paper, we propose the simple experimental method to realize the execution time of ladder diagram (LD) in programmable controllers (PCs). Characteristics of the execution time of a LD are examined experimentally by using the fundamental LD with repetition. Moreover, we establish the estimation method of the execution time of LD. Thus, the relationship between the execution time and the number of vertical rungs, logical AND and OR operations is examined by adding some contacts to the proposed fundamental LD. The experimental results are analyzed statistically. As a result, the increase of the execution time for the number of rungs is remarkable as compared with that of AND and OR operations.