NETEX-G automatically attempts to generate vias/padstacks from Gerber data even though there is no such information in the raw Gerber data. Any drill automatically creates vias and padstacks on the needed layers. In addition, "round" pads can be assigned a via automatically.

However there are times when one would not like a via to be automatically generated and you can control this (to some extent) by defining the maximum diameter the via can have -- any round pads larger than this VIASIZE setting won't become vias.

B_VIASIZE
0.400
E_VIASIZE

Line 1 - must be B_VIASIZE.

Line 2 - contains the max diameter for this via

Line 3 - must be E_VIASIZE.