Status

Status 1:
Expand Solution-Explorer > TwinCAT Project > SYSTEM > TcCOM Objects > Object (XtsProcessingUnit) > Object (XtsPart) > Object (AT2001-0250) > Data Pointer
Right-click on Status to open the context menu
Click on Change Link… in the context menu
Status 2:

The Attach Variable Status dialog box opens.

Expand Solution-Explorer > TwinCAT Project > I/O > Devices > Devices (EtherCAT) > Term 2 (AT2001-0250)
Select Status
Confirm with OK
Status 3:

A gray arrow on the variable indicates successful linking.

Further information can be found in chapter Linking details.