Publication 1756-PM004C-EN-P - October 2009 51
Organize Tags Chapter 2
Expressions
You can also use an expression to specify the subscript of an array.
• An expression uses operators, such as + or -, to calculate a value.
• The controller computes the result of the expression and uses it as the
array subscript.
You can use these operators to specify the subscript of an array.
Format your expressions as follows.
Operator Description
+Add
- Subtract/negate
* Multiply
/ Divide
ABS Absolute value
AND AND
FRD BCD to integer
MOD Modulo
NOT Complement
OR OR
SQR Square root
TOD Integer to BCD
TRN Truncate
XOR Exclusive OR
Operator Description
Format Expressions
If the operator requires Use this format Example
One value (tag or expression) operator(value) ABS(tag_a)
Two values (tags, constants, or
expressions)
value_a operator value_b • tag_b + 5
• tag_c AND tag_d
• (tag_e ** 2) MOD (tag_f / tag_g)