The types REFERENCE TO or POINTER TO are not supported by structured text (ST) programming language according to IEC 61131-3:2013. While importing the PLCopen XML file(s), these types remain unchanged. The user has to replace them manually and adapt the code accordingly.
WARNING
After import, a simple change to the supported REF_TO type is NOT sufficient as the behavior of the code may change!
Other programming environments may perform implicit dereference while assigning a reference to another reference (see following example ref_2 := ref_1;).