Unidirectional motor

My pellet extruder takes step and direction as control. We have added it as our 7th axis (A).

The problem is that we NEVER want it to run in reverse. Unlike reverse during filament extrusion (which will remove the filament from the heating area), the screw in our pellet extruder will move the melt pool from the hot area back up into the (cool) reservoir of pellets. This causes the mother of all clogs.

Right now our A direction (adir) is
net adir not.2.in <= stepgen.6.dir

I would think something like:
net adir <= FALSE

would be the solution, but it's syntactically incorrect.

I'm new to HAL, so I hope I'm just overlooking the obvious. Any help would be appreciated.

Roughtyper

You cannot "net" a signal to a constant but you can set a signal:

sets adir false

(sets means "set signal")