Patent ID: 8810398

Claim:
A container monitoring system configured to monitor access to and conditional status of a container, the system comprising: a first door controller module disposed in communication with a controller module, the first door controller module configured to receive a first random generated code from the controller module and further configured to store the first random generated code; a second door controller module disposed in communication with the controller module, the second door controller module configured to receive a second random generated code from the controller module and further configured to store the second random generated code, wherein the controller module comprises a lens and a photodetector, the lens being configured to receive an optical signal having a corresponding light pattern and direct the optical signal to the photodetector, and wherein the controller module is configured to: separately interrogate the first door controller and the second door controller; establish one or more alarm conditions based on one or more signals received from the first door controller and the second door controller; and detect a shift in position of the light pattern of the optical signal along an axis of the photodetector in response to the first door controller or the second door controller moving with respect to the controller module, wherein the one or more alarm conditions comprise an alarm condition wherein a change in a position value, associated with the shift in position of the light pattern of the optical signal, is above a predetermined threshold.