Browse Prior Art Database

Technique for Specifying LOGICAL TRIGGER Conditions for a Data Collection Device

IP.com Disclosure Number: IPCOM000061344D
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 4 page(s) / 19K

Publishing Venue

IBM

Related People

Boscove, JA: AUTHOR [+3]

Abstract

This article describes a technique which allows the data collection device to be programmed to begin capturing data based on values present in the data stream being monitored. By monitoring the data stream for a particular event, as indicated by a logical expression passed to the data collection device, it is possible to begin the data collection process only after the "triggering" condition has been met. This technique allows better us of available memory for capturing data by not storing data which has been previously determined to be of no useful value. The method described may be implemented easily by the microprocessor present in the data collection device. A technician terminal for diagnosis of automotive problems connects to the vehicle assembly line diagnostic link (ALDL).

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Technique for Specifying LOGICAL TRIGGER Conditions for a Data Collection Device

This article describes a technique which allows the data collection device to be programmed to begin capturing data based on values present in the data stream being monitored. By monitoring the data stream for a particular event, as indicated by a logical expression passed to the data collection device, it is possible to begin the data collection process only after the "triggering" condition has been met. This technique allows better us of available memory for capturing data by not storing data which has been previously determined to be of no useful value. The method described may be implemented easily by the microprocessor present in the data collection device. A technician terminal for diagnosis of automotive problems connects to the vehicle assembly line diagnostic link (ALDL). The technician terminal uses the ALDL as a communication port to the electrical system of the vehicle under test. Normal and diagnostic data is available from the ALDL. Data is read from the vehicle under test into the technician terminal where it is checked for error conditions. However, if a problem is intermittent in nature or occurs only during dynamic driving conditions, the technician terminal may be of little or no value in diagnosing the problem. It is for this situation that the Vehicle Service Monitor (VSM) has been designed. The VSM is a portable device which is used to collect data from the ALDL of the vehicle under normal driving conditions. When a problem is detected, data is collected by the VSM from the ALDL for subsequent analysis by the technician terminal. Since the VSM is a portable device, the amount of data that may be collected is limited. Therefore, it is desired to collect ALDL data only when the problem actually occurs. Several methods of triggering the collection of data have been incorporated into the VSM. If the problem is noticed by the driver of the vehicle, a trigger button may be pushed to initiate collection of data. This method of triggering the VSM is called manual triggering. The VSM also incorporates an external probe which may be connected to an electrical signal on the vehicle to indicate when the VSM should be triggered. This type of triggering is called external triggering. The type of triggering which is desired is selected when the VSM is initialized, prior to its connection to the vehicle. Some problems may not be obvious to the driver or may not result in an electrical signal change which can be monitored, but may cause certain parameters in the ALDL data stream to change. Thus, a third type of triggering is needed which will allow the VSM to be programmed to check the ALDL data stream for specific data patterns which indicate a problem with the vehicle.

This type of triggering is know as internal triggering. The method disclosed herein specifies a trigger logic expression for the purpose of checking the ALDL data stream when int...