Abstract: An automatic anomalous event detection method uses a pair of counters to count the occurrence of main triggers simultaneously with the occurrence of advanced triggers indicative of anomalous events as defined by an operator. The anomalous events may be defined as either time or voltage qualified events that occur at a much lower rate than the repetition rate of an input analog signal being measured. When the main trigger counter reaches a maximum count, the count of the advanced trigger counter is compared with a range greater than zero to less than the maximum count modified by an operator specified divider. If the advance trigger count is within the range, then an anomalous event is detected and the next advanced trigger signal causes a portion of the input analog signal to be acquired for storage in a waveform memory and subsequent display of the anomalous event.