Instruction List (IL) is a low-level, text-based programming language defined in the IEC 61131-3 standard.

It closely resembles assembly language and is used for simple, fast control logic.

Structure:

A program is made up of a series of instructions, one per line

Each instruction includes:

• An operator (e.g., LD, ST, AND, OR)
• One or more operands, separated by commas

LD – means Load or Make current result equal to the operand 

Syntax Rules:

A label may precede an instruction:

START: LD VAR1

Comments must appear at the end of a line

Empty lines can be added for clarity