Oscilloscope with detection of anomalous events during blind intervals

• US 5,841,286 A
• Filed: 02/17/1995
• Issued: 11/24/1998
• Est. Priority Date: 07/07/1993
• Status: Expired due to Term

• Current Assignee: Tektronix Incorporated (Fortive Corp.)
• Original Assignee: Tektronix Incorporated (Fortive Corp.)
• Inventors: Stoops, John F.
• Primary Examiner(s): Wieder, Kenneth A.
• Assistant Examiner(s): BROWN, GLENN WARNER
• Application Number:
  US08/390,907
• Time in Patent Office: 1,376 Days
• Field of Search: 324/76.12, 324/76.13, 324/121 R, 324/511, 324/522, 324/523, 324/76.16, 324/76.18, 340/825.04, 340/754, 364/486, 364/487
• US Class Current: 324/511
• CPC Class Codes: G01R 13/32 Circuits for displaying non-recurrent functions such as transients; Circuits for triggering; Circuits for synchronisation; Circuits for time-base expansion
• CPC Class Codes: G01R 13/345 for displaying sampled signals by using digital processors by intermediate A.D. and D.A. convertors (control circuits for CRT indicators)
• CPC Class Codes: G01R 19/17 giving an indication of the number of times this occurs , i.e. multi-channel analysers

Abstract

An oscilloscope comprises a trigger circuit for initiating display of the waveform of an input signal in response to a trigger event, at least one detection circuit responsive to the input signal for detecting occurrence of an anomalous event therein, and a counter for reporting the number of occurrences of the anomalous event that have been detected.

Claims

1. An oscilloscope comprising:

a trigger circuit connected to detect a trigger event in the input signal for initiating display of a waveform of an input signal in response to the trigger event, the trigger event being the occurrence of a predefined behavior of the input signal,

display means for displaying the waveform in response to the initiation of the trigger circuit,

at least one detection circuit independent of the trigger circuit and responsive to the input signal for detecting occurrence of an anomalous event in the input signal during a blind interval of a measurement cycle of the oscilloscope, the blind interval being an interval during which the oscilloscope is unable to process the input signal to produce a waveform display, and

means for responding to the occurrence of the anomalous event by either recording the occurrence of the anomalous event or communicating the occurrence of the anomalous event to an operator.

2. An oscilloscope according to claim 1, wherein said oscilloscope comprises control means for operating the oscilloscope in accordance with a measurement cycle comprising sequentially an active interval and the blind interval, wherein the active interval plus the blind interval form a detection interval during which the detection circuit is responsive to the input signal.

3. An oscilloscope according to claim 1, wherein the means for responding to the occurrence of the anomalous event comprises means for providing a display indicating that the anomalous event has been detected.

4. An oscilloscope according to claim 1, wherein the trigger circuit includes a trigger latch that is connected to respond to detection of an anomalous event by said detection circuit.

5. An oscilloscope according to claim 1, further comprising a peak detector means responsive to the input signal for detecting peaks thereof.

6. An oscilloscope according to claim 1, comprising a plurality of detection circuits for detecting at least two anomalous events selected from the group consisting of glitches, runt pulses, rise times longer than a selected value, and fall times longer than a selected value.

7. An oscilloscope according to claim 6, wherein the trigger circuit includes a trigger latch and means for connecting the trigger latch to respond to detection of an anomalous event by any of the detection circuits.

8. An oscilloscope according to claim 1, wherein the detection circuit is responsive to an anomalous event that is different from the trigger event.