information is supplied to a bus in a wired logic function , the potential on the bus either being pulled down to ground level or remaining at supply level . the data line in a bus is split into two parts which are interconnected via the main current channel a transistor . different supply voltages are used on the two parts . the control electrode of the transistor is connected to the lowest of the supply voltages . the transistor becomes conductive when either of the parts is pulled down . the transistor is non - conductive when none of the parts is pulled down .