SCADA software is a program that it put on the Master Terminal Unit in a PC. How to approach the design required of SCADA software?
There are several types of approaches in the design of SCADA systems:
• Centralized Processing
• Distributed Processing
• Client / Server
In this approach one computer doing all the monitoring plant so that all data stored in a database residing on one computer. This approach has several weaknesses:
• Initial cost is expensive.
• Difficulty upgrading because the system tends to fixed.
• Redundancy becomes expensive because the entire system must be duplicated.
In this approach, SCADA system is divided into several small computers (usually PCs). This approach is to overcome the weaknesses of Centralized processing. But it still has weaknesses as following:
• The complexity of communication between computers.
• Processing of data and databases must be copied to all computers, resulting low efficiency.
• There is no systematic approach to obtain data from plant devices.
This approach is similar to that used in computer networking concepts. There are several terms that must be understood first, namely:
• Server nodes: nodes that serve other nodes in the network.
• Client node: node which requested the service from the server.
Examples of this approach are: a PC that serves to display data from other computers in a network. The process that occurs is as follows:
• Client (display node) request data from server.
• Look at the database server and provide the data to be displayed by the client.
The advantage of this approach is the reduction in network workload, so that the process will take place more quickly and efficiently.