Question about Element Symbology

Question

Hello, 
 I am getting this symbol/icon near some of my nodes. If someone can please explain what the "black arrow" pointing towards the node indicates and why other nodes don't show this. 
 if someone can explain or refer me to a manual. 
 Thank you.

Yashodhan Joshi · Answer

Hello, 
 Check the junction properties and see if the "Is Constituent Source?" property is set to "True". When your nodes are sources of constituents you have the option of setting this property to "True" and specifying the concentration at that point. See this article for reference: Can a node be a constituent source? 
 See this article for details on constituent sources and types: Understanding Constituent Source Types and Constituent patterns 
 If you set the "Is Constituent Source?" property is set to "False", the arrow will go away. Check if your model is setup for constituent analysis . 
 Hope this helps.