Allen-Bradley 1756-L65 ControlLogix 5565, Programming Manual

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Rockwell Automation Publication 1756-PM004D-EN-P - September 2012 35
Organizing Tags Chapter 2
Create an Array Logix5000 controllers also let you use arrays to organize data.
A subscript (s) identifies each individual element within the array. A subscript
starts at 0 and extends to the number of elements minus 1 (zero based).
The following example compares a structure to an array.
Term Definition
Array A tag that contains a block of multiple pieces of data.
· An array is similar to a file.
· Within an array, each individual piece of data is called an element.
· Each element uses the same data type.
· An array tag occupies a contiguous block of memory in the controller, each element in sequence.
· You can use array and sequencer instructions to manipulate or index through the elements of an array.
· You organize the data into a block of one, two, or three dimensions.
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To expand an array and display its
elements, click the + sign.
To collapse an array and hide
its elements, click the – sign.
This array contains six
elements of the DINT data
type.
Six DINTs
Elements of
Timer_Presets
This is a tag that uses the Timer structure (data type).
Tag Name Data Type
Timer_1 TIMER
Timer_1.PRE DINT
Timer_1.ACC DINT
Timer_1.EN BOOL
Timer_1.TT BOOL
Timer_1.DN BOOL
−
+
+
This is a tag that uses an array of the Timer data type.
Tag Name Data Type
Timers TIMER[3]
Timer[0] TIMER
Timer[1] TIMER
Timer[2] TIMER
−
+
+
+