pdaPortDirection
For photonics ports the signals are bi-directional - also the output of a laser acts as input in the sense that if you send in optical power there, you modify the laser performance. However for a designer it is a logical output.
The same holds for a 1:2 splitter - it has a single logical input and two logical outputs, otherwise you would call it a 2:1 combiner. The geometry can be the same in optics!
Allowed values: In, Out and InOut.
Structure
This element is simple - it does not have attributes or elements. The text that fills up the... is value used.
<direction> ... </direction>
XSD The schema file can be downloaded or viewed at xPDK_Base.