DEVICE FOR INTERPRETING SFC IN CONTROLLER

摘要

PURPOSE: A device for interpreting SFC(sequential function chart) in a controller is provided to improve the speed of managing by managing the complex step of the SFC language rapidly and to reduce a memory space by using a step discriminator, the feedback of which is made by using a queue. CONSTITUTION: The device includes a Q(21), the first memory table(22), a selector(23), the second memory table(24), the third memory table(25) and the fourth memory table(26). The queue(21) stores a step discriminator activated at the beginning and a back step discriminator of the fired transition temporarily. The first memory table(22) stores a transition discriminator appropriate to the step discriminator input from the queue(21). The selector(23) stores if it is possible to fire the transition discriminator input from the first memory table(22) or not. The second memory table(24) stores and outputs the front step discriminator appropriate to the transition discriminator. The third memory table(25) stores the back step discriminator appropriate to the transition discriminator and makes a feedback to the queue(21). The fourth memory table(26) stores the condition of the activation and the inactivation of the front step discriminator and the back step discriminator.