Abstract: A DC bus circuit is disclosed for coupling multiple discrete signals from multiple discrete signal sources with multiple receivers remote from the signal sources. Each multiple signal source has two discrete positions or levels, such as opened or closed, and each signal source has an encoding resistor in series therewith, with no active components. Each encoding resistor has an ohmic value which is a discrete power of two times a reference resistor, and each signal source transmits its signal by grounding or ungrounding its resistor. Each multiple receiver is connected to its corresponding remote signal source by a common DC bus, and each receiver has a decoder circuit which compares the voltage on the DC bus with a reference voltage generated by a pair of reference resistors.