DX200 mpMotSetAccuracy for external axes

Hello all.

I noticed that mpMotSetAccuracy(value_in_um) works abnormal with external axes. For example with positioners. Any accuracy values > 0 causes the positioner to slow down in every point. Only -1 the movement smooth. Is it correct? May be this function has limited use?

And i don't understand how this thing works for rotational axes at all, because accuracy value is set in linear unit [micrometers].

Onemore thing was found during debugging. Full signature of the function is mpMotSetAccuracy(int grpNo, long acr).

So, i found that call mpMptSetAccuracy for external movegroup (grpNo=1, 2...) do nothing! Only accuracy for main group (grpNo=0) affects real accuracy for all move groups...