stepgen parameters syntax in 2.8 with Mesa 7i96

hi, i'm struggling to get my tool changer component working, and I think I have it narrowed down to these to lines :

net astep <= stepgen.3.step
net adir <= stepgen.3.dir

My axis is is step up as "s" and not "a" on stepgen 2 ( generated by the pncconf wizard) so my signals are sstep & sdir (is that even right, or is the componenent looking specifically for an A axis? ), but I can seem to find if "stepgen.X.step" and "stepgen.X.dir", are still the right parameters under linuxcnc 2.8? 

thank you all for your help
 

Those pins do not exist in a Mesa configuration,
you can just delete them