An "aktiv digital" machine is a machine where one can program an axis to automaticly move to a designated point, where it will stop exactly.
The direction the axis will move in is normally indicated by yellow diodes mounted up high on the machne near the y-axis. Only in the very latest machine iteration shown above was the direction indicted on the display of the DRO. With this "control" is was actually possible to program a complete program in the DRO to be activated line by line with the feed lever. This programming included tool radius compensation and upon completion of one line would automaticly jump to the next. This set-up is as close as one can get to NC, without actually being NC (eventhough the DRO certainly contains a calculator).