Chapter 13 Structured Texts Create the flags and the digital outputs in the global symbol table. When users edit the POU of the function block type, they have to create an input pin which receives the state code specified by the main program, and output pins which correspond to the three lights and the buzzer. Owing to the fact that the corresponding light will be displayed after the function block receives the state code specified by the main program, a CASE statement can be used in the function block. If there is another display mode, the users can add a state code, and insert a condition in the function block.
The users can insert an example of a CASE statement in the working area, and modify the statement. They can also type the structured text shown below in the working area. 13-35