Method of constraints control for oscilloscope timebase subsection and display parameters

• US 20040167727A1
• Filed: 02/25/2003
• Published: 08/26/2004
• Est. Priority Date: 02/25/2003
• Status: Active Grant

• Current Assignee: Tektronix Incorporated (Fortive Corp.)
• Original Assignee: Tektronix Incorporated (Fortive Corp.)
• Inventors: Pickerd, John J.
• Granted Patent: US 6,915,218 B2
• Time in Patent Office: Days
• US Class Current: 702/57
• CPC Class Codes: G01R 13/029 Software therefor

Abstract

An apparatus and method for constraining temporal parameters associated with the acquisition and display of signals under test.

Claims

1. Apparatus, comprising:

a signal acquisition device, for sampling a signal under test (SUT) at a sample rate S to form thereby a stream of acquired samples;

a memory, for storing sequences of said acquired samples as corresponding sample records, each sample record having associated with it a duration parameter; and

a controller, for generating a display signal suitable for use by a display device and including waveform imagery visually cooperating with temporal segment delineators;

said controller, in a first mode of operation, adapting a number of temporal segment delineators in response to said duration parameter.

2. The apparatus of claim 1, wherein:

in response to user input indicative of a new duration parameter, said controller in said first mode of operation adjusts the number of samples used to form each sample record.

3. The apparatus of claim 2, wherein:

in the case of said adjusted number of samples exceeding a threshold level, said controller in said first mode of constrains the number of samples used to form each sample record to said threshold level and adjusts the sample rate S.

4. The apparatus of claim 1, wherein:

in response to user input indicative of a new sample rate parameter, said controller in said first mode of operation adjusts the number of samples used to form each sample record.

5. The apparatus of claim 4, wherein:

in the case of said adjusted number of samples exceeding a threshold level, said controller in said first mode of constrains the number of samples used to form each sample record to said threshold level and adjusts the number of samples used to form each sample record.

6. The apparatus of claim 1, wherein:

said controller, in said first mode of operation, operates to lock an initial portion of said waveform imagery to an initial temporal segment delineator.

7. The apparatus of claim 6, wherein:

in response to user input indicative of a new duration parameter, said controller adjusts the number of samples used to form each sample record and scales the number of temporal segment delineators according to the ratio of the new and existing duration parameters.

8. The apparatus of claim 1, wherein:

in response to user input indicative of a desired number of temporal segment delineators, segmenting said waveform imagery into said desired number of temporal segments.

9. The apparatus of claim 1, wherein:

said controller, in a second mode of operation, adapting a number of temporal segment delineators in response to user input indicative of a desired number of temporal segment delineators.

10. The apparatus of claim 2, wherein:

said sample rate and record length parameters are simultaneously adjusted to provide one of a predetermined plurality of duration parameters.

11. A user interface adapted for use in a signal acquisition device, said signal acquisition device producing a display signal including a waveform layer and a grid layer, comprising:

a first user manipulable region for enabling user selection of a temporal acquisition parameter to adapt thereby a waveform representing an acquired signal under test (SUT); and

a second user manipulable region for enabling user selection of a temporal display parameter to adapt thereby a temporal portion of a display grid intended to be superimposed over said waveform.

12. The user interface of claim 11, wherein said temporal portion of said display grid is also adapted in response to said temporal acquisition parameter.

13. The user interface of claim 11, wherein said temporal acquisition parameter comprises a duration parameter.

14. The user interface of claim 13, wherein user adjustment of said duration parameter comprises an adjustment of a record length parameter.

15. The user interface of claim 14, wherein adjustment of said duration parameter beyond a limitation of said record length parameter results in an adjustment of a sample rate parameter.

16. The user interface of claim 11, wherein said temporal acquisition parameter comprises a sampling resolution parameter.

17. The user interface of claim 11, wherein said temporal display parameter defines a number of temporal grid positions of said display grid.

20. The oscilloscope of claim 17, wherein:

wherein said sample rate and record length parameters are simultaneously adjusted to provide one of a predetermined plurality of duration parameters.

18. An oscilloscope, comprising:

signal acquisition circuitry for acquiring a plurality of samples of at least one signal under test (SUT) in response to at least one timebase control signal;

signal display circuitry for displaying at least a portion of said acquired samples and a corresponding display grid; and

a controller, for modifying said at least one timebase control in response to a first user command, and for modifying said display grid in response to a second user command;

wherein;

said display grid modification comprises at least one of modifying a number of temporal grid lines and selecting a time per temporal grid line.

19. The oscilloscope of claim 18, wherein said timebase control modification causes a change in at least one of a sample rate parameter and a record length parameter of said acquisition circuitry.