The Call In metric is used to get information about who is calling a method, function, function block, and so on.
Each call to an implementation is considered, but if the same object (method, function, ...) is called twice in the same implementation, it is only counted once.
Example
Call In calculation example for IEC-61131-3 code:
METH();
// Some other implementation
METH();
Call In Result (for method METH)
Call In = 1