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