Siemens SIMATIC S7-1200 - Page 136

PLC concepts
5.4 Data types
S7-1200 Programmable controller
136 System Manual, V4.2, 09/2016, A5E02486680-AK
Example
This example shows the input parameters of a standard-access FB. The byte tag B1 is
overlaid with an array of Booleans:
Another example is a DWord tag overlaid with a Struct, which includes a Word, Byte, and
two Booleans:
The Offset column of the block interface shows the location of the overlaid data types
relative to the original tag.
You can address the overlay types directly in the program logic:
LAD
FBD
SCL
IF #OV[1] THEN
...
END_IF;
IF #DW1_Struct.W1 = W#16#000C THEN
...
END_IF;
out1 := #DW1_Struct.B1;
IF #OV[4] AND #DW1_Struct.BO2 THEN
...
END_IF;