Syntax Rules in Logic Solver Expressions

An expression is made up of operands, constants, operators, functions, comments.

Each expression must follow a specific syntax to be valid. The Expression Editor validates the expression when parsing.

The Option Explicit behavior is enforced even if the statement is not present in the expression, requiring declaration of temporary variables. 

References (Inputs, Outputs, and Other Module Parameters)

The Logic Solver subset of expressions supports only references to the inputs and outputs of the Logic Solver Calc/Logic block and to other module/block parameters within the same module. External and dynamic references are not supported.

If you do not specify the field, CV is assumed.

Relative Notation

The notation rules for referencing parameters within and outside of the LSCALC block are shown in the following table.

 Statements for Expressions in the Logic Solver

The following statement types are allowed in Logic Solver Calc/Logic expressions. Statements are separated by semicolons.

OUT1 := ABS(IN1);
'OUT2' := '^/BLOCK1/PARAM1';

IF IN1 = 1 THEN
   OUT1 := 1;
ELSE
   OUT1 := 0;
ENDIF;

Option Explicit; (* optional *)
VAR
   TEMP1;
   TEMP2;
END_VAR;

Assignment Statements

The assignment (:=) statement allows the assignment of an expression to a reference, a temporary variable or an output to locations inside and outside of the current block.

Syntax

'reference' := expression; (* only references to 'OUTx' and local module parameters are possible *)

or

tempvar := expression;

or

OUTn := expression;

The assignment (:=) statement syntax has these parts:

If...Then...Else...End_If

The IF-THEN-ELSE-END_IF structure allows you to execute conditional code in expressions. When a block tests a condition that evaluates to TRUE, it executes the set of statements after THEN. If the condition evaluates to FALSE, it executes the set of statements after ELSE.  If the condition evaluates to FALSE, and there is no ELSE, then the IF-THEN-ELSE-END_IF structure takes no action.

Syntax

If condition Then [statements]
  [Else [elsestatements]]
End_If

The IF-THEN-ELSE-END_IF statement syntax has the following parts: