US Patent 11687103 Chemical controller system and method

A method of controlling an output relay of a chemical controller is disclosed. The output relay is coupled to a pump configured to introduce at least one chemical into the aquatic application. The chemical controller controls the operation of the pump using the output relay. The method includes the step of utilizing a watchdog timer circuit to determine that a processor has failed to send a reset signal to the watchdog timer circuit before a timer of the watchdog timer circuit reaches zero. The method further includes the step of outputting a processor fault signal from the watchdog timer circuit.