A controller may send signals to {HEAD ~ one or more driver circuits} for directing {TAIL ~ operation} of the actuators 
A controller may send signals to { HEAD ~ one or more driver circuits } for directing { TAIL ~ operation } of the actuators
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH