Choosing the “trussed tower” option ensures that the software generates the wind pressure choosing the appropriate wind directionality factor Kd that is applicable for a trussed tower (Table 26.6-1 of ASCE 7-10). However this does not impact the way in which the wind load is applied on the structure. Choosing the Open Structure option ensures that the software calculates the wind load on the members considering the appropriate member sizes and subsequently applies it as member loads..