Data Logging : Remote Data Logging

Data Logging : Remote Data Logging

Sometimes it is not possible to put the computer (or people) in the location that you need data logging sensors to be. Here are some examples of data logging applications where the computer and user are located some distance away from the sensors :

Weather Forecasters : Collect information from weather stations in remote areas, weather balloons and satellites to use in their forecasts.
Space Researchers : Send probes to survey other planets. The data they record is sent back to earth to be examined and analysed by scientists.

Information collected by the sensors must be sent back to the computer to be analysed. There are two different ways in which this can be done :

Transmission	The data that is collected by the sensors can be transmitted electronically to the computer. Methods of communication such as telephone lines, radio links or satellites are used to transmit the data.
Storage and Collection	The data that is collected by the sensors can be stored in a small amount of RAM contained in a device called a data logger. The data logger is located near the sensors. When the data needs to be analysed a person must go and collect the data logger and take it to where the computer is. The data can then be transferred into the computers memory using a simple cable.

The transmission method is usually best because the data is available straight away to be analysed by the computer. A person does not need to go and collect it. On the other hand the storage and collection method is usually much cheaper. Sometimes only the transmission method can be used. Nobody could go to the space probe to collect the data it had stored in its data logger!

Collecting data using sensors and sending it over a long distance to a computer to be recorded and analysed is called remote data logging.

GCSE ICT Companion 04 - (C) P Meakin 2004