Browse Prior Art Database

Fault Diagnosis

IP.com Disclosure Number: IPCOM000084670D
Original Publication Date: 1975-Dec-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 4 page(s) / 99K

Publishing Venue

IBM

Related People

Books, AK: AUTHOR [+2]

Abstract

In a computer system, program interrupt is used in combination with simple hardware for diagnostic purposes in place of more expensive complex diagnostic hardware. Selected logic signals, related to the problem symptoms, are used to set the program interrupt. The interrupt invokes an interrupt routine which includes test and sense instructions for isolating the cause of intermittent errors.

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 54% of the total text.

Page 1 of 4

Fault Diagnosis

In a computer system, program interrupt is used in combination with simple hardware for diagnostic purposes in place of more expensive complex diagnostic hardware. Selected logic signals, related to the problem symptoms, are used to set the program interrupt. The interrupt invokes an interrupt routine which includes test and sense instructions for isolating the cause of intermittent errors.

In Fig. 1, I/O device 10 is assumed to be a multifunction card machine that reads unit record cards serially by column. Each column is sampled by a read emitter pulse generated within I/O device 10.

I/O device 10 is connected to the computer system via attachment 20 which is part of or connected to a microcontroller, not shown. The microcontroller counts the read emitter pulses and transfers the data read to the central processor of the computer system. If a read emitter pulse is dropped, the data read will not be stored at the proper location in the computer system, thus causing problems.

The failure or dropping of the read emitter pulse within attachment 20 is difficult to detect, because of the many places where it could occur. The suspected locations are selected and the signals thereat are used for requesting an interrupt. The interrupt request signals are counted in the central processing unit and a comparison is made with the value of the counter in the microcontroller for counting read emitter pulses. Equal and unequal comparisons are then used in pinpointing the location where the read emitter pulse was dropped.

The read emitter pulse exits I/O device 10 on line 11 and is applied to logic converter block A in attachment 20. The output of block A at point 1, as well as points 2, 3 and 4, are selected as sources for initiating diagnostic interrupt requ...