Minecraft wiki entry for Miscellaneous, associated text: A multiplex circuit transmits multiple signals on a single transmission line by using a control line to choose which signal should be transmitted or received. The control line may be either clocked, to transmit the signals sequentially, or selection, to simply choose which signal to transmit. The control line(s) can also be substituted with two synchronized pulse generating clocks. Then only one line is necessary. However, they have to stay synchronized for the transmission to be correct. This can be done using a daylight sensor.