Patent ID: 7596958

Claim:
A refrigeration case monitoring system comprising: a first fiber optic cable positioned at a first end of a refrigeration case door and configured to transmit a first signal indicative of a first refrigeration case condition; at least one second fiber optic cable configured to transmit a second signal indicative of a second refrigeration case condition that is different than the first refrigeration case condition; a control system having a first sensing channel and at least one second sensing channel, wherein the control system is configured to receive and process the signals from the first and at least one second fiber optic cables, wherein the first signal is compared to a first threshold value, and the second signal is compared to a second threshold value, and wherein the control system generates a first output related to the first refrigeration case condition if the first signal exceeds the first threshold value, and generates a second output related to the second refrigeration case condition if the second signal exceeds the second threshold value; and a fiber optic fault checking system having a third fiber optic cable positioned at a second end of the refrigeration case door and configured to transmit a third signal indicative of the first refrigeration case condition, the fiber optic fault checking system comparing the first and third signals to identify a faulty fiber optic cable, wherein the fiber optic cable is identified as faulty when the first and third signals are different.