For Conduits - Pipes and Conduit Channels - the following structures types can be Start (Upstream) Nodes
- Inlets
- Headwalls/Endwalls
- Outfalls
- Cross Section node
For Channels from Node only these two types are supported:
- Cross Section Node
- Endwalls with a Defined Cross Section
For the current Bentley Training Workspace, the only Endwall with a defined Cross Section is: Headwall > With Wingwalls > Culvert Headwall.
The critical definition here is the Headwall Prototype "Has Cross Section?" Property is True.
When set to True the properties necessary for a downstream Channel from Node are set here.
A Headwall having a Cross Section does not restrict what conduit can be attached to it in any way (only an absence does).
Note: the current Workspace has one other Headwall Prototype. If you were to define a Cross Section in it, all Headwalls would be able to support a downstream Channel from Node.