{HEAD ~ the first device} is driven by the first power supply, and capable of performing a communication via the bus in the condition in which the pull up {TAIL ~ voltage} is equal to either of the first predetermined voltage and the second predetermined voltage, 
{ HEAD ~ the first device } is driven by the first power supply , and capable of performing a communication via the bus in the condition in which the pull up { TAIL ~ voltage } is equal to either of the first predetermined voltage and the second predetermined voltage ,
HEAD HEAD HEAD HEAD HEAD HEAD HEAD 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 TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH