Introduction to SCADA


#1

SCADA or Supervisory Control and Data Acquisition, as the name indicates, it is not a full control system, but rather focuses on the supervisory level.

As such, it is a purely software package that is positioned on top of hardware to which it is interfaced, in general via Programmable Logic Controllers (PLCs), or other commercial hardware modules.

SCADA systems are used not only in industrial processes: e.g. steel making, power generation (conventional and nuclear) and distribution, chemistry, but also in some experimental facilities such as nuclear fusion.

The size of such plants range from a few 1000 to several 10 thousands input/output (I/O) channels. SCADA systems used to run on DOS, VMS and UNIX; in recent years all SCADA vendors have moved to NT and some also to Linux.

It is a large scale control system for automated industrial processes like municipal water supplies, power generation, steel manufacturing, gas and oil pipelines etc. SCADA also has applications in large scale experimental facilities like those used in nuclear fusion.

SCADA systems monitor and control these operations by gathering data from sensors at the facility or remote station and then sending it to a central computer system that manages the operations using this information.

An industrial SCADA system will be used for the development of the controls .The SCADA systems in terms of their architecture, their interface to the process hardware, the functionality and the application development facilities they provide.

SCADA systems have made substantial progress over the recent years in terms of Functionality, scalability, performance and openness such that they are an alternative to In-House development even for very demanding and complex control systems as those of Physics experiments.

SCADA System

The sheer size and of the operations we saw earlier demands that the control system be equally elaborate to handle the requirements. This is where SCADA scores. The SCADA system is equipped to manage anything from a few thousands to a million input/output channels.

The technology is still evolving and we can expect an expansion of the market for SCADA. A fully fledged SCADA system is made up of signal hardware for input/ output, networks, control equipment, user interface (sometimes called the Human-Machine Interface or HMI), communication equipment and the software to go with it all.

And here we are talking about the central command system of SCADA. The central system is often miles away from where the operations take place. Thus the system also needs on-site sensors to collect and monitor data.

Why SCADA?

SCADA is an acronym that denotes Supervisory Control And Data Acquisition. SCADA is a control system with applications in managing large-scale, automated industrial operations. Factories and plants, water supply systems, nuclear and conventional power generator systems etc are a few examples.

The SCADA system consists of one Central Terminal (which could be several miles away from the site of operations) and one or several remote sensor terminals close to the site of operations.

The sensor units send data to the central terminal which monitors and manages this data. Communication devices, a user interface and the software to make it all work together complete the picture of what makes a SCADA system.

Benefits of SCADA

A SCADA system when applied properly can help industries to save time and money. One reason is that with SCADA, you can eliminate the need for site visits by your personnel for inspection, adjustments and data collection. SCADA software enables you to monitor the operations in real time. It can also make modifications to the system, auto-generate reports and trouble-shoot.

Thus once the system is installed, it reduces operational costs and improves the efficiency of the set-up. SCADA systems are equipped to make immediate corrections in the operational system, so they can increase the life-period of your equipment and save on the need for costly repairs.

It also translates into man-hours saved and personnel enabled to focus on tasks that require human involvement. Further, the auto-generated reporting system ensures compliance with regulatory principles.