Rockwell Automation Logix5000 Controllers I/O and Tag Data Programming Manual - Manual (Page 52)

Chapter 2 Organize tags
You can use these operators to specify the subscript of an array.
Format your expressions as shown in the following table.
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)
Array subscript out of range
Every instruction generates a major fault if the array subscript is out of range.
Transitional instructions also generate a major fault even if the rung is false. The
controller checks the array subscript in these instructions even if the rung is false.
Example:
52 Rockwell Automation Publication 1756-PM004E-EN-P - October 2014