Topic 217

Data logging by Dwarkesh

Data logging is the practice of recording sequential data, often chronologically. In computerized data logging, a computer program may automatically record events in a certain scope in order to provide an audit trail that can be used to diagnose problems. Examples of physical systems which have logging subsystems include process control systems, and the black box recorders installed in aircraft. Many operating systems and multitudinous computer programs include some form of logging subsystem. Some operating systems provide a syslog service (described in RFC 3164), which allows the filtering and recording of log messages to be performed by a separate dedicated subsystem, rather than placing the onus on each application to provide its own ad hoc logging system. In many cases, the logs are esoteric and hard to understand; they need to be subjected to log analysis in order to make sense of them. Other servers use a splunk to parse log files in order to facilitate troubleshooting; this approach may yield correlations between seemingly-unrelated events on different servers. Other enterprise class solutions such as those from Log Logic collect log data files in volume and make them available for reporting and real-time analysis.

The performance characteristics of a car can be monitored through its diagnostic port. There are several ways to do this; one way is by using a handheld device with software already installed and the appropriate cable to hook into the diagnostic port. Another method is to use a PDA loaded with specialized software and employ a special cable that plugs into the diagnostic port. Finally, a PC can be used, laptops generally work best, using specialized software and connecting it to the car with a specially-made cable.

Data logging a car allows one to observe how well the car is running. A data logger can be used to help tune the car, especially if modifications have been made to the vehicle. The reason it helps is that it logs various parameters in the engine such as ignition timing, injector pulse, RPM, knock/detonation, barometer pressure, temperature, oxygen sensors, and various other sensor data. Using the information that is provided (and either some sort of piggy-back or standalone system), a user can change the injector pulse width so that the engine is fed more or less fuel, increase or decrease ignition timing, and other changes. Such changes are made to make the car run more reliably or achieve higher performance.

When the computer is used for measurement, the tasks it performs can be summarized as follows:

Collect data from external sensors.
Store data in computer memory.
Display data in graphical form.
Process data; i.e. perform calculations.
The advantages of using a computer to collect data are:
Graphical display
Analyzing tools
Calculating aids
Continuous recording
Simultaneous recording
Period logging

Remote Logging. Data may be collected independently from the microcomputer using a data-logger. - Data-logger may be sited in locations which are not convenient for computers - Computer is made free for other activity - This is well-suited to longer term experiments. - The data may be viewed retrospectively e.g. Field work: climatic factors over few hours Laboratory experiments: germination of peas etc.


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Data logging by Romeo

Data logging is the practice of recording sequential data, often chronologically. Data logging is used by almost every single company in the world. The advantage of the damage log in, it is easier to keep track of the data and easier to organize them since computer will have the abilities to organize the data for you. One disadvantage of data logging is that sometimes the computer memory reaches its limit the data base would crash and you might loose all the data and possibly you won’t be able to recover any of those.

Now days Electronic companies are improving their server which made the date crashing less possible. In computerized data logging, a computer program may automatically record events in a certain scope in order to provide an audit trail that can be used to diagnose problems.

Examples of physical systems which have logging subsystems include process control systems, and the black box recorders installed in aircraft. Many operating systems and multitudinous computer programs include some form of logging subsystem. Some operating systems provide a system log service which allows the filtering and recording of log messages to be performed by a separate dedicated subsystem, rather than placing the onus on each application to provide its own ad hoc logging system.

In many cases, the logs are esoteric and hard to understand; they need to be subjected to log analysis in order to make sense of them. Other servers use a spelunk to parse log files in order to facilitate troubleshooting; this approach may yield correlations between seemingly-unrelated events on different servers. Other enterprise class solutions such as those from Log Logic collect log data files in volume and make them available for reporting and real-time analysis