Electronic stepper to determine elevator car position, with automatic error correction and immunity from power failure

Elevator car floor position indicating means, responsive to a hoistway input signal indicative of said car passing a floor in an up and down direction, for providing, respectively, an increment and decrementing output signal indicative of the floor position of said car, comprising:

• an initialization switch, being settable to be indicative of a selected reference position of said car, responsive to an interrogating signal, for providing a reference signal indicative of said reference position as set by said settable initialization switch;
• and
• signal processing means, responsive to:
• said hoistway input signal, for providing said incrementing and decrementing output signal;
• a request for initialization signal, for providing said interrogating signal;
• and
• both a correction signal indicative of the position of said car being at said reference position and said reference signal, for providing said output signal with a referenced magnitude indicative of the same floor as that indicated by the magnitude of said reference signal and for thereafter incrementing and decrementing said output signal starting from said referenced magnitude;
• wherein said signal processing means provides a display signal having a magnitude indicative of the magnitude of said output signal and wherein said indicating means further comprises display means, responsive to said display signal, for displaying said magnitude of said display signal, said indicating means further comprising toggle switch means, responsive to manual toggling, for providing a toggle signal to said signal processing means for incrementing or decrementing said magnitude of both said output signal and said display signal.