This chapter considers the jump instruction, which enables part of a program to be jumped over, and the way in which subroutines in ladder programs can be called up. Subroutines enable commonly occurring operations in a program to be repeatedly called up and used over again.
A function often provided with PLCs is the conditional jump. We can describe this as:
IF (some condition occurs) THEN perform some instructions ELSE perform some other instructions
Such a facility enables programs to be designed ...