[NTG-context] How can one center or align a float?

Hi all, How is it possible to have a STEPchart be midaligned, or right-aligned, as one may do this with figures, tables, and FLOWcharts? An example is here: %%%%%%%%%%%% \usemodule[steps,mathml] \starttext \startbuffer[test-chart] \startSTEPtable \cell {$c=2a+3b$} \text {with $a=5$} \cell {$c=10+3b$} \text {and $b=6$} \cell {$c=10+18$} \text {we get} \cell {$c=28$} \stopSTEPtable \stopbuffer How can one center the following \type{\STEPchart}? \getbuffer[test-chart] \stoptext %%%%%%%%%%%% I should add that \startalignment[middle], or \placefigure do not have any influence on the alignment of the above example. Thanks in advance an best regards: OK