External hardware that connects to I/O devices such as sensors, motors, monitors, machines, etc. can be connected to the invention via {HEAD ~ I/O boards} that receives and transmit {TAIL ~ digital signals}, representing control information, to the bus 
receives
External hardware that connects to I / O devices such as sensors , motors , monitors , machines , etc . can be connected to the invention via { HEAD ~ I / O boards } that receives and transmit { TAIL ~ digital signals } , representing control information , to the bus
OTH OTH OTH OTH OTH OTH OTH OTH 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 HEAD HEAD OTH REL OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH