Composite trigger for a digital sampling oscilloscope

摘要

A Composite Trigger for a DSO provisionally honors a conventional hardware trigger by algorithmically investigating the content of the associated Acquisition Record for a selected signal attribute (a S/W Trigger). If found, the hardware trigger is fully honored by displaying the Acquisition Record with a previously selected time scale and with the time reference set to where in the trace the selected signal attribute occurs. The selected attribute may include the occurrence of a stated value or stated range of values for any automatic measurement upon a trace that the 'scope is otherwise equipped to perform. In addition to being based on existing automatic measurements, the Composite Trigger can also be satisfied whenever subsequent investigation determines that a segment of trace described by the Acquisition Record does or does not pass through one or more zones defined relative to an existing time reference. The Composite Trigger can also be based on whether a trace can be interpreted as exhibiting a selected serial bit pattern, or, upon whether the trace represents an edge that is not monotonic.