Variables can be declared with a maximum nesting of 9 elements (the DB itself is one of those elements). Accessing “DB1”.e2.e3.e4.e5.e6.e7.e8.my_var is possible, but not any further nesting. This is the limitation present in TIA.

AX allows for deeper nesting, but S7WEBAPI does not handle those nestings.

Workaround: Limit the nesting

There is work in progress on this issue.

See also:
Inxton/AXOpen#51