SCADA Systems, PLC & RTU Solutions

Why are SCADA Systems Important?

SCADA, PLC and RTU solutions create an information pathways that allow various equipment to provide information and data to the home base or central host. The central host may be physical hardware on-premise or could be virtually anywhere. Data acquisition of process information provides status and control of all types of industrial processes. Whether you want to monitor your HVAC system, water treatment plant, power generation equipment, or other intelligent machinery at any location, the SCADA, PLC and RTU equipment is as critical to continuous operation of the plant as the plant itself.

How to Design SCADA Systems

The success or failure of any large-scale IT/OT project, such as SCADA, depends on the design, product selection, design planning, implementation strategies, testing discipline and people collaboration. There are several subsystems in an enterprise SCADA system which may include remote terminal units (RTUs), programmable logic controllers (PLCs), distributed control systems (DCS), telemetry infrastructure, data acquisition and edge servers, human-machine interfaces, process historian software and so forth. All SCADA Solution components need to seamlessly interact with one another, and particularly if there is a large distance between system elements. Communications latency, system availability and access to critical spares and support are all important inputs to a total system design. The design team at Parasyn utilises proven techniques to ensure that the best implementation strategy is developed based on the customers’ requirements. The Parasyn team have experience designing the project structure as well as the technologies required to deliver customised solutions what work. When you have to guarantee a system for life, you design it better.

What is the best project structure for SCADA projects?

Most small non-critical SCADA systems do not require significant design investment. When a system grows in size, or connects with many devices, the design and how the data management activity is to be organised and performed must be designed to ensure sufficient resources are available for the performance expected. The breadth of knowledge required widens.

For larger systems, there is likely a need for a number of SMEs (subject matter experts) to come together to collaborate. Being familiar with the system components is insufficient grounding to understand the principles involved in doing systems design. Engineers capable of doing end to end systems design have experience work in teams contributing their expertise but fully appreciating where their domain begins and ends.  Most large-scale system’s design is performed by groups of engineers who are organised by discipline and who also have a strong understanding of the impact each component of a system has on other components of the same system. For this reason, it is unwise to appoint more people to the team to get a design done quicker. This is usually counterproductive.

The ideal background for doing design is people who understand user requirements and are committed to getting clarity before design begins. This means working closely with stakeholders who may have a different vocabulary and may be more or less educated on the subject matter. Noting can be taken for granted when putting a team together because we are working with people, not machines.

Why Choose Parasyn for your Industrial IT Solutions

Parasyn is an Australian IIoT Company which has years of experience developing customers solutions for efficiently managing assets. Parasyn specialises in solutions for industry and critical infrastructure businesses including oil and gas, water, energy, and transportation.

Most of Parasyn’s industry awards are related to systems design for critical infrastructure where a group of engineers collaborated with the customer’s stakeholders to sure up concepts, document the design and then implement the system safely. Even though it is nice to win awards for boutique and unique first-class projects that are cutting edge, these don’t come along every day.

Most, but not all that Parasyn does, includes an element of creativity. “Systems of success” is the formula that Parasyn applies to deliver projects without having to make up the plan every single time. Parasyn does not spend time working out how to run jobs, how to develop design processes, organizing how teams are to work together or preparing templates to deliver technology projects because it’s all been done before.

Parasyn’s creativity and ingenuity is directly applied to solving problems and customising how technology can be deployed successfully. Even though requirements must sometimes be discovered by inquiry, how services and projects are delivered is not guess work. This provides assurance of outcomes.

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Parasyn’s creativity and ingenuity is directly applied to solving problems and customizing how technology can be deployed successfully. Even though requirements must sometimes be discovered by inquiry, how services and projects are delivered is not guess work. This provides assurance of outcomes.

What is a SCADA network?

SCADA is used by many professionals as a general term that describes all of the information systems and infrastructure use to manage a group of assets. Sometimes SCADA subsystems may be identified which include telecommunications, IT infrastructure, instrumentation, wiring, domains, WAN, LAN and software. Sometimes SCADA systems share infrastructure with other enterprise systems. This definition is in contrast to calling a single software application SCADA.

How do SCADA systems work? What is a HMI?

SCADA systems are a culmination of subsystems and components. They may be complex or very simple. A simple system could consist of one PLC used to control a pump or piece of equipment and a HMI (Human Machine Interface) could be a touch panel.

Who uses SCADA?

Almost all essential services and industry use SCADA. The defence force, public infrastructure and utilities use SCADA, manufacturers use SCADA to control various types of production machinery, building automation systems in hospitals use a form of SCADA, transport companies, mining companies and virtually anyone who needs to operate critical assets reliability, more reliability that what is typical for desktop consumer grade applications.

What are the Applications used in SCADA?

Some may argue that SCADA only applies to the software system used across the greater enterprise which manages groups of assets, however, the SCADA software itself could be the very same software being used locally on your device. In other words, the plant software or the enterprise software is the same but has been configured specifically for a user or at the enterprise level. For this reason, there is sometimes confusion about the reach of the SCADA system.

The SCADA software may include visualization, alarm management tools, client distribution technologies, reporting and other software specific to the industry itself. Some SCADA systems allow integration with 3rd Party enterprise systems. SCADA software is synonymous with customized visualization of an enterprise’s asset footprint. The SCADA development environment makes it possible to organised information logically so that standards can be applied for maintaining each asset, instrument or device that is part of the “system”.

What is a PLC?

Programmable Logic Controllers (PLCs) are a control device similar in concept to a computer. They are very similar to an RTU. The operating system is purpose built (embedded) and designed specifically for control applications where routine activities must be done reliably and regularly without failure. There is not tolerance or provision for a “blue screen” and having someone do a restart at their leisure. These high-speed controllers may have options for redundant CPUs, power supplies, communications, I/O cards, and be safety certified depending on the application and brand of the PLC. All of these options come at a price, therefore, the choice of which PLC may be determined by a number of factors. These factors may include:

What is a DCS?

A Distributed Control System (DCS) is generally used for controlling continuous processes plant. In the 70-80’s, DCS were used for controlling many process plants. In time, as PLC’s improved in performance and reliability, they have replaced DCS in some applications particularly safety grade PLCs due to their compact size and wider experience by the Automation Industry profession.

A DCS solution is usually a very significant investment for the asset owner or asset manager. A DCS solution is synonymous with a quality solution and a price tag to match. In recent years as the PLC market has penetrated and replaced many DCS applications, DCS vendors have begun to release “lower grade” DCS solutions with less features and a matching price tag so that they are able to use their solutions in applications which are now typical for PLC solutions.

What is the difference between a DCS and PLC?

Generally, a DCS hardware platform is fully integrated and certified to only operate with its own SCADA Platform. SCADA systems are event driven and the core component of the DCS is state driven. These important distinctions help to explain the reason that DCS systems are used for applications like continuous process mining plants and oil rigs.

In many cases the DCS solution may not be as flexible as off the shelf SCADA, PLC and RTU systems, however, the DCS solution is intended for applications where repeatability is paramount, and flexibility is less important due to the limited number of customizations required for operations.

What are the best protocols for SCADA?

Time series protocols win this challenge hands down every time. Today, the most established over the air protocol for distributed SCADA systems is DNP3 (Distributed Network Protocol). There are others to choose from, however, with the exception of the real time protocol Modbus, they are less common and this means more challenging to support and maintain. Even though DNP3 is very well established by many vendors, vendors sometimes do not have their interfaces independently certified. Vendors sometimes develop their own “protocol stack” from scratch. This means to ensure full compatibility with other certified products, either certification or thorough testing must occur each time you choose to use a new device or software application combination.

DNP3 is a time series protocol. This means the value of the process variable (sampled data) is recorded with the time and data in the field device. As long as the field device is synchronized accurately with a time source (e.g. NTP or GPS) then the events created by the DNP3 RTU or device can be used for SOE (Sequence of Events) systems. This is very common practice in Rail and Power industries and is quickly becoming the pseudo standard for other utilities throughout the world.

What are the greatest problems with SCADA systems?

Without explaining why, the biggest problems we see with SCADA systems can be summarized in the follow list:

 Too many connections to the SCADA platform inhibiting its ability to perform its primary purpose of data acquisition and alarm notification.
 Device selection by personal preference at the cost of system design criteria.
 Incorrect selection of network protocols.
 No data management plan, ie how much data do I need for the business, do I have the communications network to support this, do I have storage for the data payload.
 Documented design which can be used to scale up the systems as it needs to grow, downsize the system, split the system, or replace it.
 Having too many “thick” client applications all accessing information at the same time instead of using other technologies like Enterprise Historians which are designed for high performance data access.
 Too many customisations which compromise the performance of the application subsystems.