Patent Document ID: 4698780
Application ID: 06785378
Patent Status: 1

Claim One:
1. A method of monitoring an operating elevator system for a malfunction related to predetermined sequentially performed functions, comprising the steps of: providing binary logic signals having one of two logic levels from an elevator system which are pertinent to a predetermined sequence of functions to be monitored for a malfunction, storing unique user defined event starting and stopping conditions which define the start of an event and the end of an event, respectively, in terms of the logic levels of at least certain of said binary logic signals, detecting when each of said binary logic signals changes logic levels, with each such change being a state change of the event, providing a correct binary image of the event by the steps of: detecting the occurrence of the unique user defined event starting and stopping conditions while the elevator system is operated to correctly perform the sequence to be monitored, storing the logic levels of all of the binary logic signals upon each state change which occurs between the detection of the unique event starting and stopping conditions, and timing each event to detect the occurrence time of each state change relative to the start of the event, and monitoring the operation of the elevator system by providing binary images of said event each time said event occurs, with said monitoring step including the steps of: detecting the occurrence of the unique user defined event starting and stopping conditions while the elevator system is in operation, storing the logic levels of all of the binary logic signals upon each state change and timing each event to detect the occurrence time of each state change relative to the start of each event, to provide a temporary binary image of the event, comparing each temporary binary image with the correct binary image to detect differences, and storing a temporary image for diagnostic purposes when the comparing step detects a difference between the temporary binary image and the correct binary image.