Translation of Automation Control Programs for Deductive Verification(Ladder Diagram to Why Code)

A special-purpose microcontroller PLC, widely used in industrial automation, is using a specially designed graphical language LD(Ladder Diagram). This paper proposes a method to use a verification condition generator Why for verifying LD programs. For proof of the verification requirement you can use a theorem prover such as Coq to prove the proof obligations. In order to apply Why to LD programs, LD programs should be represented in the why specification and verification requirements be given. This paper shows the verification process of LD programs by using automatic translation and Why.