Delta RMC151 - Manual (Page 342)

RMC70/150 and RMCTools User Manual
For examples of expressions, see the Condition Expressions and Assignment Expressions
topics.
For examples of user programs that use expressions, see the Programming Examples
topic.
Parts of an Expression
The building blocks of all expressions are:
Operators These are symbols that represent an action to be performed, such as +,
-, /, etc.
Functions These are predefined, named formulas, such as SIN(), MIN(),
LOG_EVENT(), etc.
User
Functions
User functions are custom functions created or imported by the user.
User functions can be edited in the User Function Editor.
Operands These are the elements that the operators and functions work on:
Type Examples
Constant
Value
3, 10.345
Register (tag) _Axis[0].ActPos, %MD8.3
Variable SampleVariable1 (must exist in the variable
table)
Keywords These are words that have a specific meaning for the code, such as IF,
THEN, ELSE, True, False, etc.
Comments Comments are a good way of documenting the code.
Expression Color-Coding
Expressions are color-coded as follows:
Blue: Keywords
Dark Red: System-defined tags
Beige: User-defined tags
Black: Operators and numbers
Magenta: Functions
Red with yellow background: Invalid value
Troubleshooting Expressions
For help on troubleshooting expressions, see the Troubleshooting Expressions topic.
Operators and Functions
For details on the operators and functions used in expressions, see the Operators and
Functions topics.
5.13.2. Assignment Expressions
An assignment expression assigns a value to a register. Assignment expressions are used in
the Expression (113) command in a User Program, and in User Functions.
Assignment Expression Basics
An assignment expression must follow this format:
322 Delta Computer Systems, Inc.