Activate the Calltree pane using . The calltree only displays the root entries, tasks or POUs that are not assigned to a task. The called POUs and the used global variables are displayed hierarchically in a tree structure. The calltree shows you whether functions or function blocks were used in a program and how dependent they are on each other:
To display extended information in the Calltree pane, select from the context menu, or select the information item in the navigator options.