97BPLC concepts
4.4 Data types
S7-1200 Programmable controller
System Manual, 11/2011, A5E02486680-05
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A Struct variable begins at an even-byte address and uses the memory to the next word
boundary.
4.4.6
PLC data type
The PLC data type editor lets you define data structures that you can use multiple times in
your program. You create a PLC data type by opening the "PLC data types" branch of the
project tree and double-clicking the "Add new data type" item. On the newly created PLC
data type item, use two single-clicks to rename the default name and double-click to open
the PLC data type editor.
You create a custom PLC data type structure using the same editing methods that are used
in the data block editor. Add new rows for any data types that are necessary to create the
data structure that you want.
If a new PLC data type is created, then the new PLC type name will appear in the data type
selector drop drop-lists in the DB editor and code block interface editor.
Potential uses of PLC data types:
●
PLC data types can be used directly as a data type in a code block interface or in data
blocks.
●
PLC data types can be used as a template for the creation of multiple global data blocks
that use the same data structure.
For example, a PLC data type could be a recipe for mixing colors. You can then assign this
PLC data type to multiple data blocks. Each data block can then have the variables adjusted
to create a specific color.
4.4.7
Pointer data types
The pointer data types (Pointer, Any, and Variant) can be used in the block interface tables
for FB and FC code blocks. You can select a pointer data type from the block interface data
type drop-lists.
The Variant data type is also used for instruction parameters.
