Version 7 of ATPDraw stores group hierachically and introduce new recursive methods of node naming. A fundamental assumption is that the content of a group inherit its parent object. The benefit is a much faster node naming process (compile).
It is important to realize that node names inside the group cannot influence back on the parent object. This applies also to the phase sequence.
An illustration of illegal node naming is found in example Exa_4g.acp:
Inside the mechanical network a node is named BUSMG, but this node is connected to another node that gets it's node name from the parent (referenced nodes shown with red circles). This will create a duplicate node conflicts, with a warning but unfortunately unmanaged. Consequenctly the link between the parent component and the content is broken. The solution in this case is to remove the BUSMG node name from the group and instead name the node on the top level. Generally, manual node naming should not be done prior to Compression/Grouping. The BUSMS node name is stricly internal and will not cause a conflict.
There are also some special illegal group nodes:
From left to right:
Phase sequence cannot be determined by the group.
Both sides of transposition have the same node name and cannot both be externally connected.
A Single-phase node of a Splitter cannot be externally connected (phase sequence cannot be determined by the group).
Both sides of a connection cannot be externally connected.
The single-phase side of a connection cannot be externally connected (phase sequence cannot be determined by the group).
A fix for phase sequence restriction has been implemented as part of making a new group, but how robust this is uncertain. The advice is to avoid the five mentioned situations.