Networked Data Collection
The concept behind EDASnet is to provide Environmental Data collection systems using distributed computer processing and saving the results in a standard database format thus making use of modern computer networking technology.
The following diagram describes a typical environmental data collection system with two Tide Gauges and a Weather Station directly connected to a single PC, the outlying '+' characters indicate the logical point to expand the systems, in this case by making more connections directly to the PC ...
Single PC systems tend to be legacy designs that have evolved around existing equipment, probably having been added to at various times in their history and almost certainly the result of ad hoc software updates and changes. The basic concept of a single PC acting as a central data collection and display point has proved to be a very cost effective solution to the problem of collecting and recording environmental data. These systems without doubt have proved their reliability in collecting and storing environmental data, however as computer and information technologies progress these systems are starting to show their limitations. With testimony from many users the general problems areas with these single PC systems are as follows ...
The following diagram outlines the logical design of a system that performs the same task as the previous single PC system but is designed around networking principals. As with the previous diagram the '+' characters indicate the points at which the system can be expanded ....
From the above diagram it can be seen that the system can be expanded almost indefinitely by either making connections to existing PCs or by adding PCs to the network. The single PC system can actually be simulated using the network model with all programs (Clients) running on one machine and the interconnecting network being the internal data bus. In most applications the network would consist of a number of interconnected computers using a standard cabling and protocol scheme supported by the operating system. The location and use of each machine would be determined by normal constraints such as nearness to peripheral devices (in this case Tide Gauges and Weather Stations) or by the power of the machine (e.g. fast machine with large hard disk would be the data storage and server node). Output nodes would be computers on the desks of users wishing to see or have access to the data. Input nodes would be computers running Input Client programs and connected to the environmental devices either directly by cable or indirectly by telemetry.
The major difference between the design of 'single PC' and the 'Network' Environmental Data collection model is that the network model has been broken into logical 'components'.
Each component executes as a single task which under modern operating systems can be run concurrently on the same or different computers across a network. The main components identified in a Networked EDAS system are as follows ....
Each of the above software components can be tailored to run across a network of computers and provide a 'scaleable' system. By having a distributed system there are several features which add robustness to the data collection system ..
Data collected using the EDASnet system is saved in a standard, commercially available database format. Currently this format uses products which are designed using the Microsoft JET database engine technology such as Access and SQL server.
The database is a common holding area for a variety of data sets that can loosely be described as 'Environmental'. Each parameter has two relational Tables associated with the data being collected ...
To date there are two major areas of data which have been addressed by Lymtech and are included within the database design ...
Using a database is not the most efficient way of storing environmental data but it is the best compromise of storing the information in a structured form and retrieving it a a later date. With the low cost of modern data storage, the benefits of being able to retrieve data using database tools such as Selection and Sorting, then being able to process the data in commercially available products such as Spreadsheets greatly outweigh the initial costs of hardware.
Copyrightę2011 Lymtech LLC - Last modified: 02-07-2011