Instrumentation and Electrical (I&E) Technician Practice Test 2026 - Free I&E Technician Practice Questions and Study Guide

Structured Text is designed for high-level programming of PLCs. It resembles traditional programming languages like Pascal or C, using variables, data types, and common operators. This makes it straightforward to write complex arithmetic expressions and logical decisions, including multi-step calculations, loops, and conditional branches. You can define data types, arrays, and functions, which lets you create reusable, readable code for sophisticated control algorithms. The other PLC languages are more pictorial or closer to hardware: Ladder Diagram mirrors relay logic, Function Block Diagram links functional blocks, and Instruction List is a low-level, line-oriented language not as suited for elaborate calculations. So for expressing arithmetic and logic in a high-level form, Structured Text fits best.