I have board layout in allegro 16.2.I want to add smd flying probe(test point) on through hole via at bottom side of pcb.Please suggest.
Well, if I could insert a snippet of the Testprep dialog I could show you, but I don't see a way to do that. I shall open that as a separate discussion. so in general you want to enable bare board - Pin Type = Via, Pad type = Thru, Layer = Bottom
The remaining parameters are pretty straight forward. Since it might be trial and error initially you'll probably want to use the Overwrite for the Execute Mode. This flushes the previously tagged TP's. Frankly I'm not a fan of the Allegro TP generation. Among other things; it should allow the user to set which which via or pin padstacks are eligible in automatic mode. I don't want it tagging small or soldermask covered vias as TP's. Instead it considers every via or pin padstack eligible, and thus I never get the results I need. I don't know - could be me.