Allen-Bradley Logix5000

398 Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Chapter 8 Array (File)/Misc. Instructions (FAL, FSC, COP, CPS, FLL, AVE, SRT, STD, SIZE)
Execution:
Example 1: Find the number of elements in dimension 0 (first dimension) of array_a. Store
the size in array_a_size. In this example, dimension 0 of array_a has 10 elements.
Relay Ladder
Structured Text
SIZE(array_a,0,array_a_size);
Example 2: Find the number of elements in the DATA member of string_1, which is a string.
Store the size in string_1_size. In this example, the DATA member of string_1 has
82 elements. (The string uses the default STRING data type.) Since each element
holds one character, string_1 can contain up to 82 characters.
Relay Ladder
Structured Text
SIZE(string_1.DATA[0],0,string_1_size);
Condition Relay Ladder Action Structured Text Action
Prescan The rung-condition-out is set to false. No action taken.
Rung-condition-in is false The rung-condition-out is set to false. N/A
Rung-condition-in is true The instruction executes.
The rung-condition-out is set to true.
N/A
EnableIn is set N/A EnableIn is always set.
The instruction executes.
Instruction execution The instruction finds the size of a dimension. The instruction finds the size of a dimension.
Postscan The rung-condition-out is set to false. No action taken.
Size in Elements
Source array_a[0]
255
Dim. To Vary 0
Size array_a_size
10
SIZE
Size in Elements
Source string_1.DATA[0]
'$00'
Dim. To Vary 0
Size string_1_size
82
SIZE