Reacting to unusual waveforms

• US 6,188,384 B1
• Filed: 06/05/1998
• Issued: 02/13/2001
• Est. Priority Date: 06/05/1998
• Status: Expired due to Term

• Current Assignee: Tektronix Incorporated (Fortive Corp.)
• Original Assignee: Tektronix Incorporated (Fortive Corp.)
• Inventors: Sullivan, Steven K., Gerlach, Paul M.
• Primary Examiner(s): Powell, Mark R.
• Assistant Examiner(s): HAVAN, THU THAO
• Application Number:
  US09/092,118
• Time in Patent Office: 984 Days
• Field of Search: 345/134, 345/441, 345/147, 345/507, 345/168, 345/516, 345/136, 345/133, 345/112, 345/135, 315/1, 364/921, 734/65, 734/62, 736/02, 735/96, 368/115, 445/145, 445/130, 445/148, 342/391, 342/389, 333/48, 333/00
• US Class Current: 345/440.1
• CPC Class Codes: G01R 13/0263 for non-recurrent functions, e.g. transients
• 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)

Abstract

Unusual waveforms are defined in terms of how many “new” pixels are affected by the process of rasterizing them. New pixels can be those not yet affected by the rasterization of any waveform in the current set of acquisitions, or to be those that have had higher values in their raster memory location but have now been decayed to below a defined value. Once detected, such waveforms can be re-rasterized with extra intensity or into a different color by using a reserved range of values of those storable in the raster memory. Alternatively, the special region of values can be used as a counter/timer to maintain the pixels associated with unusual waveforms at a brightest intensity value, or in the color equivalent, for an extended period of time. User input can be used to affect the definition of “new” pixels and to control the special persistence given to unusual waveforms. Unusual waveforms can also be saved in long term memory. Multiple decay functions and regions of values in the raster memory locations can be used as described above, or to produce a fast rate of decay in a bright visible region and a user adjustable slower rate of decay in a dimmer region, thus making recently acquired waveforms look bright and “lively”, while older waveforms appear to be relatively gray and stable. The same techniques can be employed when color is used either along with or as a substitute for intensity variations.

Claims

1. A method for reacting to the automatic detection of unusual waveforms during, monitoring of a generally repetitive electrical signal by a digital oscilloscope, the method comprising the steps of:

automatically detecting an unusual waveform;

halting further waveform acquisitions;

freezing the display;

re-rasterizing the unusual waveform with enhanced intensity or a different color or both, and

displaying the re-rasterized unusual waveform with enhanced intensity or a different color or both.

2. A method for reacting to the automatic detection of unusual waveforms according to claim 1 wherein a level of the enhanced intensity is greater than any level of intensity used to display normal waveforms.

3. A method for reacting to the automatic detection of unusual waveforms according to claim 1 wherein the different color is different than any color used to display normal waveforms.

4. A method for reacting to the automatic detection of unusual waveforms during monitoring of a generally repetitive electrical signal by a digital oscilloscope, the method comprising the steps of:

automatically detecting an unusual waveform; and

re-rasterizing the unusual waveform with enhanced intensity or a different color or both;

wherein a level of the enhanced intensity for unusual waveforms is maintained for a longer period of time than the period of time that a level of intensity for usual waveforms is maintained.

5. A method for reacting to the automatic detection of unusual waveforms according to claim 4 wherein the different color for unusual waveforms is maintained for a longer period of time than the period of time that a color for usual waveforms is maintained.

6. A method for reacting to the automatic detection of unusual waveforms according to claim 4 further comprising the step of:

applying a persistence decay function with a relatively low rate of decay to intensity-related values stored in a raster memory that are greater than the intensity-related values used in connection with usual waveforms.

7. A method for reacting to the automatic detection of unusual waveforms according to claim 5 further comprising the step of:

applying a persistence decay function with a relatively low rate of decay to color-related values stored in a raster memory that are greater than the color-related values used in connection with usual waveforms.

8. A method for reacting to the automatic detection of unusual waveforms according to claim 4 further comprising the step of:

mapping all of the intensity-related values that are greater than the intensity-related values used in connection with usual waveforms to the same intensity for display.

9. A method for reacting to the automatic detection of unusual waveforms according to claim 5 further comprising the step of:

mapping all of the color-related values that are greater than the color-related values used in connection with usual waveforms to the same color for display.