loadusr -Wn vfd hy_vfd -n vfd -d /dev/ttyUSB0 -p none -r 9600

net spindle-cmd-rpm-abs => vfd.speed-command
net spindle-cw spindle.0.forward => vfd.spindle-forward
net spindle-ccw spindle.0.reverse => vfd.spindle-reverse
net on spindle.0.on => vfd.spindle-on