Rockwell Automation GMLC Reference Manual - Manual (Page 499)

Publication GMLC-5.2 - November 1999
462 The Expression Builder
Continuing with the previous example, these two expressions do produce
the same result—the parentheses force the addition to be performed
before the multiplication:
100 * (2 + 10)
(2 + 10) * 100
Both of these expressions are evaluated as:
2 + 10 * 100 = 12 * 100 = 1,200
[ ]
Brackets
The numeric keypad’s bracket key enters an indirect variable reference.
See Indirect Variable in System Functions in this chapter for more
information on indirect variable referencing.
Expression Operators
The mathematical and logical operations, which can be performed on the
elements (constants, variables, etc.) of an expression, are called
expression operators. In general, an expression operator must separate
(come between) any two elements in an expression.
Select expression operators from the Operator Scrolling List, shown at
left. Scroll the list until the desired symbol appears, then click on it to
insert it into the expression at the current cursor location. All expression
operators are standard ASCII characters, or combinations of ASCII
characters. Therefore, you can also insert them into the expression
directly from the keyboard.
!
ATTENTION: Do not use the [ ] key in place of the
( ) key to change the precedence of operations in an
expression!