In other words, an active control signal 47 turns on an isolation device to allow {TAIL ~ a potential} to be conducted from one location to {HEAD ~ another location} 
In other words , an active control signal 47 turns on an isolation device to allow { TAIL ~ a potential } to be conducted from one location to { HEAD ~ another location }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD