Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Identifying Machine Faults

IP.com Disclosure Number: IPCOM000049537D
Original Publication Date: 1982-Jun-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 3 page(s) / 55K

Publishing Venue

IBM

Related People

Perkins, RJ: AUTHOR

Abstract

Machine operation faults are detected and located by generating check words from uncorrelated signals in a tested machine and comparing the words with predetermined correct words.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 68% of the total text.

Page 1 of 3

Identifying Machine Faults

Machine operation faults are detected and located by generating check words from uncorrelated signals in a tested machine and comparing the words with predetermined correct words.

Coding techniques test a microcode-driven logic section of a machine 1, such as a copier, whose uncorrelated input/output (I/O) signals are viewed as one data word 2. All I/O word 2 lines in the copier 1 are updated synchronously by a clock. A zero-crossing detector 6 monitors the number of clock cycle zero- crossings until the next I/O change. Each time that any I/O line is changed from its prior state, word 3 is developed by a check generator 4 and placed in a storage 5.

In a known correctly-operating copier 7, the number of I/O words 8, encoded by a check word encoder 9, plus the number of intervening clock cycles, calculated by a counter 10, form an execution pattern representing "correct" operation. This check word 13 data is placed in a correct word storage 11 for later comparison (by comparator 12) with check word data in storage 5 from the tested copier 1. The comparison clock cycle variations between check words, failing signals and copier execution failures.

In a copier under test 1, I/O lines DO-D15 in a word 2 are assigned meanings: DO equals Switch 1, D6 equals Lamp Drive, etc. Each line is assigned a "1" if it is active, and a "0" if it is not. The lines are numbered sequentially in binary code, the 1st, 2nd, 4th, 8th, and 16th lines being reserved for check bits: Lines Code

C0 00001

C1 00010

DO 00011

C2 00100

D1 00101

D2 00110

D3 00111

C3 01000

D4 01001

D5 01010

D6 01011

D7 01100

D8 01101

D9 01110

D10 01111

C4 10000

D11 10001

D12 10010

D13 10011

D14 lOl00

D15 10101

If, in an example, lines D...