In a preferred embodiment, the frame emulates a workpiece cassette and the distance sensors provide a numerical output of {HEAD ~ the distance} to {TAIL ~ the workpiece} 
to
In a preferred embodiment , the frame emulates a workpiece cassette and the distance sensors provide a numerical output of { HEAD ~ the distance } to { TAIL ~ the workpiece }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL