Identifiers

Introduction

An Identifier is used to name different elements within a program. For example: a Variable Declaration, a Derived Data Type, or a Function.

Identifiers must conform to these rules:

An identifier can consist of any combination of: Letters, Numbers and Underscore.
A Letter is any Unicode character classified as a letter. Volt and Вольт are both valid identifiers.
An identifier cannot begin with a number.
Case is not significant in identifiers. Pressure is equivalent to PRESSURE.
All the characters in an identifier are significant.

To learn about other IEC 61131-3 Common Elements.

For a list of all Unicode character codes used in IEC 61131-3 code.

For the meaning of terms used in Fernhill SCADA.