Siemens SIMATIC S7 System Manual page 123

Example
You call SBR0 from OB1, using a global symbol called INPUT1 as an input parameter of the
subroutine.
Inside the Local Variable Table of SBR0, you have defined a local variable called FIRST as
an input parameter.
When OB1 calls SBR0, the value of INPUT1 is passed to FIRST.
The data types of INPUT1 and FIRST must match.
If INPUT1 is a REAL and FIRST is a REAL, the data types match. If INPUT1 is a REAL but
FIRST is an INT, the data types do not match and the program cannot be compiled until this
error is corrected.
Viewing the variable table
To view the variable table for the POU selected in the program editor, select "Variable table"
from the Component drop-down list in the Windows area of the View menu.
Note
You can put the variable table on the quick access toolbar (Page 105) for easy access.
S7-200 SMART
System Manual, V2.3, 07/2017, A5E03822230-AF
Programming concepts
5.6 Variable table
123