A quote from a Lincoln Electric welding instructor, "The triangular waveform is useless. It's there because the engineers wanted it." This feature is also on my machine, so I guess Lincoln decided if they put it in the slick marketing brochure it would sell more welders? The old brochure also stated that it was "optimized for 5P". As well as Lincolns machines work, their literature needs more rigorous editing. For instance, in their Procedure Handbook, they recommend a 3/16" 6012 electrode for a fillet weld on 10 ga. steel. This chart has been reprinted in this book and other brochures I have come across. There are others, but I need to get back to work......