An agricultural communication system is provided that enables sensor-to-sensor link communications of peripheral farming devices (planters, fertilizer or pesticide applicators, etc.) so as to enhance diagnostics for locating system faults and blockages. The system also provides a means to operate with single-faults present with real-time diagnostics to the operator. The point-to-point communications also facilitates simplified installation by automatically determining the sensor addressing based on the physical connection of the sensors. Since the sensor-to-sensor daisy chain bus system is self-configuring there is no dependency on the sensor manufacturing data or sequential installation procedure to define the sensor address as required in other prior art systems. A dual power supply from each end of the looped bus with independent switching provides operation in the presence of single-faults, and a diagnostic mode combined with sensor power supply voltage measurements provides fault location.