The master continues to poll {TAIL ~ another slave} while {HEAD ~ data} comes into the slave at time slot 4 
The master continues to poll { TAIL ~ another slave } while { HEAD ~ data } comes into the slave at time slot 4
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH