; checks if the selector is empty and not currently resting on its endstop.
M98 P"mmu/lib/check-endstop.g" A{global.mmu_selector_axis}
M98 P"mmu/lib/check-endstop.g" A{global.mmu_extruder_axis}
  
if #sensors.gpIn > global.mmu_selector_trigger && sensors.gpIn[global.mmu_selector_trigger] != null && sensors.gpIn[global.mmu_selector_trigger].value == 0
  abort "Filament is loaded into selector"