Abstract: An elevator door monitor eliminates the need to use customized input devices or modules in an elevator door monitoring system. The elevator door monitor employs differential amplifier circuits, one circuit for each of a plurality of signals to be monitored regarding an elevator car, each signal corresponding to a separate input into a microcontroller unit (“MCU”). Each differential amplifier circuit electrically communicates with a respective input terminal of the MCU, which can include a memory resource storing settings associated with respective elevator control parameters. A user can enter each setting using a peripheral input device. These settings provide system customization in lieu of hardware components, allowing the elevator door monitor to function as a universal system that can monitor a variety of elevators.

Abstract: An elevator door monitor includes a differential amplifier having an input and an output, the input configured to electrically communicate with a source configured to output one of a change-of-state voltage, and a change-of-state voltage value, with respect to an elevator control parameter, the differential amplifier configured to produce an output voltage correlating to a magnitude of the change-of-state voltage or to the change-of-state voltage value; and a microcontroller in communication with the output of the differential amplifier, the microcontroller configured to convert the output voltage from the differential amplifier to a numeric value, compare the numeric value to a setting value, and responsive to a determination that the numeric value reaches a threshold associated with the setting value, send a signal to an output relay control module, the signal comprising one selected from the group of a “true” signal and a “false” signal.