In this chapter we introduce many of the common programming elements that are used with all of the IEC languages. An understanding of how elements such as variables and data types are used is necessary before it is possible to go on to develop programs using Structured Text or any of the other languages. We will see that IEC 1131-3 provides an extensive range of common elements that can be used both with the textual languages Structured Text (ST) and Instruction List (EL), and with the graphical languages Function Block Diagram (FBD) and Ladder Diagram (LD).

Inspec keywords: visual languages; visual programming; control engineering computing; IEC standards

Other keywords: textual language; instruction list; structured text; graphical languages; common programming elements; IEC languages; ladder diagram; function block diagram

Subjects: Control engineering computing