Fault detection system with redundant product teach verification

A fail-to-safe fault detection system, comprising:

• a) a sensor system to monitor containers as said containers move along a production line, said containers having machine-readable indicia thereon, the sensor system being operative to:
• read said indicia and compare data encoded therein with reference data stored in the sensor system or to apply an algorithm to the encoded data,
• determine whether the encoded data is associated with a match condition, said match condition reflecting that the encoded data is associated with predetermined properties or characteristics;
• in response to a match condition, determine a pass result;
• and
• otherwise determine a fail result;
• the sensor system having at least the following operating states:
• a first state in which the sensor system provides a first output associated with the pass result,
• a second state in which the sensor system provides a second output associated with the fail result, said second state being a default operating state;
• and
• a third state in which the sensor system provides a third output indicative of a failure or malfunction of at least one component of the sensor system;
• and
• b) a fail-to-safe controller to detect the third output and, in response thereto, transmit an alert signal to a production line control system, said production line control system being operative to start and stop the production line and to notify a line operator that the sensor system has failed or is malfunctioning;
• c) a product verification module to verify reference data being input in the sensor system, wherein the sensor system compares the inputted reference data to data encoded in said indicia, the sensor system requiring an authorization input signal from a user to verify that the reference data has been inputted into the sensor system correctly or has been input by an authorized user, wherein
• if the sensor system does not receive the authorization input signal, the sensor system enters or remains in the third state or the second state;
• and
• otherwise the sensor system is permitted to enter the first state.