Automatic period and frequency measurements
AssigneeTektronix, Inc.
InventorHenry G. Fox
Life of this patent
Estimating the term…
Abstract
An automatic period and frequency measurement feature for an analog oscilloscope uses a single sweep signal and a delay trigger to detect edges. The sweep rate for the sweep signal is set to the highest rate that provides at least one cycle of the input signal on a display. By varying a programmable level that is compared with the sweep signal, a first event after the start of the sweep is searched for. Once a first event is located, then a second event is searched for in the same manner, reducing the sweep rate if necessary to provide the second event on the display. From the programmable levels corresponding to the first and second events a period and frequency are computed and displayed.
Claims14
A method of automatically determining a time interval between two events in an input signal comprising the steps of:
- initiating a sweep signal at a measurement sweep rate having a sweep interval that encompasses at least one cycle of the input signal;
- searching the input signal during the sweep interval for a first event as a function of a programmable delay time from the start of the sweep interval, the programmable delay time when the first event occurs being a first event time;
- searching the input signal during the sweep interval for a second event that occurs after the first event as a function of the programmable delay time, the programmable delay time when the second event occurs being a second event time;
- and
- computing the time interval between the first and second event times.
Dependencies are inferred from the claim text.