SCADA systems have been considered to be involved in parallel with the growth of modern computing technology. There are three main generations of SCADA systems which will be listed as seen below:
- First Generation (Monolithic) When SCADA based systems were first evolved, the idea of registering as a rule focused on ―mainframe‖ frame-works. Systems were for the most part non-existent, and each unified frame-work remained solitary. Subsequently, SCADA frameworks were independent frame-works with for all intents and purposes no network to different frame-works. WANs that were executed to speak with RTUs were structured considering a solitary reason that of speaking with RTUs in the field and that’s it. Availability to the SCADA ace station itself was extremely constrained by the frame-work merchant. Associations with the ace normally were done at the transport level by means of a restrictive connector or controller connected to the Central Processing Unit (CPU) backplane. Repetition in these original frame-works was practiced by the utilization of two indistinguishably prepared centralized server frame-works, an essential and a reinforcement, associated at the transport level. The reserve frame-work’s essential capacity was to screen the essential and takeover in case of an identified disappointment. This sort of backup activity implied that almost no preparing was done on the reserve frame-work. Figure shows regular original SCADA design.
2. Second Generation (Distributed)
The up and coming age of SCADA frameworks exploited turns of events and improvement in framework scaling down and LAN innovation to circulate the handling over numerous frameworks. Various stations, each with a particular capacity, were associated with a LAN and imparted data to one another continuously. “These stations were average of the little PC class, littler and more affordable than their original processors. A portion of these conveyed stations filled in as interchanges processors, fundamentally speaking with field gadgets, for example, RTUs. Some filled in as administrator interfaces, giving the human-machine interface (HMI) for
framework administrators. All things considered, others filled in as figuring processors or database servers. The appropriation of individual SCADA framework works over numerous frameworks gave all the more preparing capacity to the framework in general than would have been accessible in a solitary processor. The systems that associated these individual frameworks were commonly founded on LAN conventions and were not fit for coming to past the restrictions of the neighborhood condition. A portion of the LAN conventions that were utilized were of an exclusive sort, where the merchant made its own system convention or form thereof as opposed to pulling a current erratic the rack. Figure explain the second Generation SCADA Architecture Distribution of framework usefulness across organize associated frameworks served not exclusively to build preparing power yet in addition to improve the repetition and dependability of the framework all in all. Instead of the straightforward essential/reserve failover plot that was used in some original frameworks, the conveyed design frequently set all stations inside the LAN in the condition of online for all the time. It is worth to specify that, the WAN has been used to speak with various gadgets in the circumstance were unaltered by the LAN advancement availability between neighborhood stations at the SCADA ace. Such interchanges systems were restricted to RTU conventions and would not be available for different sorts of system traffic.
3. Third Generation – Networked
The current period of SCADA pro station configuration is solidly related to that of the ensuing age, with the basic differentiation being that of open edge work designing rather than a dealer controlled, elite condition. There are up ’til now different sorted out edge works, sharing master station limits. There are still RTUs utilizing shows that are shipper selective. “
The huge improvement in the third time is that of opening the casing work configuration, utilizing open models and shows, and making it possible to proper SCADA helpfulness over a WAN and not just a LAN. Open standards take out a portion of the constraints of past periods of SCADA outline works. The utilization of off-the-rack outline works makes it more straightforward for the customer to interface pariah periphery contraptions, (for instance, screens, printers, plate drives, tape drives, etc.) to the casing work or conceivably the framework. This licenses SCADA dealers to store up their improvement in a district where they can expand the estimation of the casing work that of SCADA pro station programming. The huge improvement in third period SCADA outline works begins from the usage of WAN shows, for instance, the IP for correspondence between the ace stations and trades equipment.