Engine analyzer with pattern library linked to vehicle id and display

Abstract

An engine analyzer having a dual-trace digital oscilloscope includes a memory for storing a library of digitized waveform patterns, the patterns being stored together with identifying data for each pattern and lists of groups of patterns respectively corresponding to different vehicles and/or engines. The analyzer includes a user interface for inputting identifying information relating to the vehicle under test, a waveform acquisition module and a central processor for cooperation with the memory and the oscilloscope for acquiring, digitizing and storing an analog input waveform from the vehicle engine and displaying it on a first trace of the scope in accordance with selected display parameters. The system automatically selects a stored list of patterns corresponding to the vehicle under test and then compares the items in that list one at a time with each of a sequence of search criteria, which criteria may include the particular input pickup lead from which the input waveform is acquired and the sweep selected for the display of that waveform, eliminating from the list any library pattern which fails to meet all the search criteria to produce a set of relevant library patterns which can then be displayed selectively, one-at-time, on the second trace of the scope.