Curiosity Bites : SCADA

Very recently CoolHax Labs received a few Industrial Automation Projects. In these projects there were a few terms that I heard for the very first time, like SCADA, HMU, RTU etc. but SCADA got into my brains. I wanted to discover more about SCADA. So let me explain what exactly SCADA is and how it works.

SCADA stands for Supervisory Control And Data Acquisition, using SCADA you can conjure varying images in the industry which you should.

What is SCADA ?

SCADA system is a collection of both software and hardware components that allows supervision and control of plantss both locally and remotely. The SCADA also examins and collects and processes data in real-time. Human Machine Interface or HMI Software facilitates interaction with field devices such as pumps, Valves, motors and sensors, etc. Also within the SCADA software is the ability to log data for historical purposes.

The structural design of a standard SCADA System starts with Remote Terminal Unit or RTU and or Programmable Logic controllers or PLCs.

RTUs and PLCs are Microprocessors that communicate and interact with field devices such as valves, pumps and HMIs. That communication Data i routed from the processors to the SCADA computers where the software interprets and displays the data allowing for operators to analyse and react to system events.

Before SCADA plant personnel had to moniter and control industrial processes via selector switches, push buttons and dials for analoge signals, this meant that plant had to maintain personnel on site during production in order to control the processes. As manufacturing grew and sites became more remote to nature, relays and timers where are used to assist in the supervision and control of processes with these devices employed fewer plant personnel were required to be onsite in orerder to oversee and control operations.

While relays and timers did provide some level of automation the panels required for these devices took up valuable real-estate. Troubleshooting was a nightmare and reconfiguring was difficut at best. These issues in conjuction with the need to grow even larger industrial plants helped to facilitate the birth of automation.

Trolling industrial plants via processors became a reality in the 1950s, gas and oil utilities and manufacturing were major users of these new technologies an supervisory control. About a decade later telemetry came on the scene to offer even more remote capabilities with automated communication and data transmission to remote monitoring locations. Another decade later the term SCADA was used to describe systems with PLC’s and micro processors that were being used for the monitoring and control of automated processes on an even greater scale than ever before.

SCADA back then was anything but practical, there were colossal machines, mainframes really and since networking was not yet in the picture they were standalone units. In the next couple of decades the 80s & 90s with computer systems getting smaller the advent of LAN and HMI software, SCADA System were able to connect to related systems. Unfortunately though communication were typicaly proprietary which meant that connections outside of the particular vendor of the SCADA system were not allowed. This early SCADA was coined and distributed SCADA Systems. Later in the 90s an 2000s SCADA began to implement open system architectures with communications protocols that were not vendor specific.

As you can imagine this opened up SCADA’s ability to connect with varying vendors. This newer and more improved SCADA was then called a networked SCADA System. newer and more improved SCADA unfortunately didn’t last long, with computer technology growing rapidly, IT development quickly gathered steam. The default database for IT became Structured Query Language or SQL Databases. SCADA developers didn’t implement these standard databases so SCADA became out of date rather quickly, when other technologies so rapidly changed.

Current data SCADA system have adapted to the changing technologies and have a greater advantages of the older SCADA systems. With the adaptation of morder IT standards such as SQL and web-based applications, today’s SCADA allows for real-time plant information to be accessed from anywhere around the world. Having this data at opertors fingertips facilitates improved plant’s operations, allowing for responses SCADA System queues based on field collected data and system analysis. These operator interactions can be from a computer right on the plant floor to an office building in some other region in the world.

Advancing technologies have indeed made the world seem like a very small place, relatively speaking. And because the SCADA system software has typically adopted the SQL database model, historical collection of data may be logged and used in trending applications to further improve plant’s processes as well as creating mandated record keeping for some of the industries out there.

Essentially SCADA is a collection of hardware and software collections. This collection of components begins with real-time data collected from plant floor devices such as pumps, valves and transmittors. These components don’t have to be from a particular vendor, they just need to have a communication protocol that the processor can utilize. Data collected from the field devices is then passed to the processor such as PLCs. From the processor, the data is distributed to a system of network devices. These devices may be HMIs, end user computers, & servers.

On the HMI or end use computer graphical representation of the operatioons exist for operator interactions, such as running pumps and opening valves. This data may also be analysed and used to enhance plant production and troubleshoot problems.

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