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