97BPLC concepts
4.4 Data types
S7-1200 Programmable controller
92
System Manual, 11/2011, A5E02486680-05
To create an array from the block interface editor, name the array and choose data type
"Array [lo .. hi] of type", then edit "lo", "hi", and "type" as follows:
●
lo - the starting (lowest) index for your array
●
hi - the ending (highest) index for your array
●
type - one of the data types, such as BOOL, SINT, UDINT
Table 4- 25 ARRAY data type rules
Data Type
Array syntax
Name [index1_min..index1_max, index2_min..index2_max] of <data type>
All array elements must be the same data type.
The index can be negative, but the lower limit must be less than or equal to the upper limit.
Arrays can have one to six dimensions.
Multi-dimensional index min..max declarations are separated by comma characters.
Nested arrays, or arrays of arrays, are not allowed.
The memory size of an array = (size of one element * total number of elements in array)
Array index
Valid index data types
Array index rules
ARRAY
Constant or
variable
USInt, SInt, UInt, Int, UDInt,
DInt
Value limits: -32768 to +32767
Valid: Mixed constants and variables
Valid: Constant expressions
Not valid: Variable expressions
ARRAY[1..20] of REAL
One dimension, 20 elements
ARRAY[-5..5] of INT
One dimension, 11 elements
Example: array
declarations
ARRAY[1..2, 3..4] of CHAR
Two dimensions, 4 elements
ARRAY1[0]
ARRAY1 element 0
ARRAY2[1,2]
ARRAY2 element [1,2]
Example: array
addresses
ARRAY3[i,j]
If i =3 and j=4, then ARRAY3 element
[3, 4] is addressed
4.4.5
Data structure data type
You can use the data type "Struct" to define a structure of data consisting of other data
types. The struct data type can be used to handle a group of related process data as a single
data unit. A Struct data type is named and the internal data structure declared in the data
block editor or a block interface editor.
Arrays and structures can also be assembled into a larger structure. A structure can be
nested up to eight levels deep. For example, you can create a structure of structures that
contain arrays.
