A fault tolerant communication and blockage monitoring system for a product dispensing unit, the system comprising: at least one peripheral electronic control unit adapted to monitor product output from the product dispensing unit; at least one master control module adapted to communicate with the at least one peripheral electronic control unit, wherein the at least one master control module further includes sensor loop diagnostics; a control area network communications bus configured to interconnect the at least one peripheral electronic control unit with the at least one master control module; and a first plurality of sensor units, characterized in that the first plurality of sensor units is configured and operatively connected in a daisy chain configuration to form a sensor loop that is operatively coupled to said at least one master control module, each of said sensor units within the loop being connected to a ground line and to a power bus or source on either end of said daisy chain configuration in the monitoring system, each of said sensor units further connected at a first end of the sensor loop with a first communication line and connected at a second end of the sensor loop with a second communication line so as to have dual communication in two directions around a communication loop within the sensor loop and individual communication lines between each sensor unit, wherein power to and communication between each of the sensor units is maintained upon occurrence of one of a power loss or a communication line loss on the first or second end of the sensor loop, and wherein the sensor loop diagnostics of the at least one master control module provides a location of a wiring fault, power loss or communications loss of a plurality of sensor loops having a fault in the one of the power bus and communications lines in at least one sensor loop. at least one peripheral electronic control unit adapted to monitor product output from the product dispensing unit; at least one master control module adapted to communicate with the at least one peripheral electronic control unit, wherein the at least one master control module further includes sensor loop diagnostics; a control area network communications bus configured to interconnect the at least one peripheral electronic control unit with the at least one master control module; and a first plurality of sensor units, characterized in that the first plurality of sensor units is configured and operatively connected in a daisy chain configuration to form a sensor loop that is operatively coupled to said at least one master control module, each of said sensor units within the loop being connected to a ground line and to a power bus or source on either end of said daisy chain configuration in the monitoring system, each of said sensor units further connected at a first end of the sensor loop with a first communication line and connected at a second end of the sensor loop with a second communication line so as to have dual communication in two directions around a communication loop within the sensor loop and individual communication lines between each sensor unit, wherein power to and communication between each of the sensor units is maintained upon occurrence of one of a power loss or a communication line loss on the first or second end of the sensor loop, and wherein the sensor loop diagnostics of the at least one master control module provides a location of a wiring fault, power loss or communications loss of a plurality of sensor loops having a fault in the one of the power bus and communications lines in at least one sensor loop.