CPC G06F 13/4247 (2013.01) [G06F 13/4004 (2013.01); G06F 13/4072 (2013.01); H04L 5/04 (2013.01); H04L 25/4917 (2013.01)] | 9 Claims |
1. A transmission device, comprising:
a first driver configured to generate a first signal of a plurality of signals, wherein the first signal has a first voltage level;
a second driver configured to generate a second signal of the plurality of signals, wherein the second signal has a second voltage level different from the first voltage level;
a comparator;
a third driver connected to the comparator; and
circuitry configured to:
determine, based on a third voltage level at a point on a communication line when a current is drawn from the communication line, whether the communication line is connected to a receiving device, wherein the point is toward a cable on the communication line;
control the third driver to change a threshold voltage of the comparator, wherein the change of the threshold voltage of the comparator is based on
the determination that the communication line is connected to the receiving device, and
the second voltage level of the second signal generated by the second driver; and
output, based on the determination that the communication line is connected to the receiving device, the plurality of signals having different voltage levels to the communication line at different timings.
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