Method of displaying continuously acquired data on a fixed length display

• US 5,684,507 A
• Filed: 09/07/1994
• Issued: 11/04/1997
• Est. Priority Date: 09/07/1994
• Status: Expired due to Term

• Current Assignee: Fluke Corporation (Fortive Corp.)
• Original Assignee: Fluke Corporation (Fortive Corp.)
• Inventors: Schipholt, Martin Lutke, Rasnake, William F.
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): TRAN, VUI
• Application Number:
  US08/301,938
• Time in Patent Office: 1,154 Days
• Field of Search: 345/134, 345/138, 345/140, 345/133, 345/232, 345/132, 345/148, 395/164, 348/448
• US Class Current: 345/440.1
• 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

A method of displaying continuously acquired measurement data in a display with a fixed number of pixels is provided. Measurement data is provided at a predetermined fixed sample rate independent of a pixel rate which is equal to or less than the sample rate. The measurement data is convened to pixel data which includes the minimum, maximum, and the average of the measurement data gathered and the pixel data is plotted to the pixels at a pixel rate. At the end of the fixed number of pixels of the display, the pixel values are compressed to half the fixed number of pixels and the pixel rate is halved, thereby doubling the time scale. This process can continue indefinitely, requiring no operator intervention or prior knowledge to set a total measurement time. Furthermore, the sample rate is independent of the pixel rate so that a tradeoff of sample rate and total measurement time need not be made.

Claims

1. A method for displaying continuously acquired measurement data on a display having a fixed number of pixels along a horizontal time scale comprising:

(a) calculating pixel information from said continuously acquired measurement data which is acquired at a sample rate;

(b) plotting said pixel information to free pixels of said display at a pixel rate along said horizontal time scale which is less than or equal to said sample rate;

(c) at the end of each sweep along said horizontal time scale, compressing said pixel information into a portion of said fixed number of pixels according to a compression ratio wherein a remaining portion of said fixed number of pixels become said free pixels and said pixel information remains valid; and

(d) reducing said pixel rate according to said compression ratio.

2. A method for displaying continuously acquired measurement data according to claim 1 wherein said compression ratio is two to one.

3. A method for displaying continuously acquired measurement data according to claim 1 wherein said pixel information comprises a minimum value, a maximum value, and an average value.

4. A method for displaying continuously acquired measurement data according to claim 3 wherein said minimum value, said maximum value, and said average value remain valid after compressing said pixel information.

5. A method for displaying continuously acquired measurement data according to claim 3 wherein said minimum value, said maximum value, and said average value are plotted to a graphical display.

6. A method for displaying continuously acquired measurement data on a display having a fixed number of pixels along a horizontal time scale comprising:

(a) calculating pixel information from said continuously acquired measurement data which is acquired at a sample rate;

(b) plotting said pixel information to free pixels of said display at a pixel rate along said horizontal time scale which is less than or equal to said sample rate;

(c) at the end of each sweep along said horizontal time scale, compressing said pixel information into a first half of said fixed number of pixels according to a compression ratio wherein a second half of said fixed number of pixels become said free pixels and said pixel information remains valid; and

(d) reducing said pixel rate by one half.

7. A method for displaying continuously acquired measurement data according to claim 6 wherein said pixel information comprises a minimum value, a maximum value, and an average value.

8. A method for displaying continuously acquired measurement data according to claim 7 wherein said minimum value, said maximum value, and said average value remain valid after compressing said pixel information.

9. A method for displaying continuously acquired measurement data according to claim 7 wherein said minimum value, said maximum value, and said average value are plotted to a graphical display.