Originally, SCADA systems were designed for Supervisory Control and Data Acquisition, providing a reliable means of aggregating the analysis being performed by multiple RTUs.  But with today’s high-speed production demands, SCADAs are required to perform Calculation and Analysis in real time on the plant floor, effectively combining the once disparate worlds of HMI and SCADA.  This enables your SCADA system to act as a Supervisory Calculation and Data Analysis tool – a capability that poses a huge advantage for manufacturers.

Using SCADA as an HMI:  Closing the Gap

In the past, Human Machine Interface (HMI) applications were simply that – the interface that existed between humans and the machines running the plant floor.  Early HMI engineers would program HMI screens onto as many individual RTU panels as existed across an enterprise.  The RTUs could be spread out across a single plant or around an extended facility, provided they were connected via a LAN (Local Area Network) or a WAN (Wide Area Network).

Data being compiled by each individual RTU would be fed across that LAN/WAN pipeline to a centralized SCADA system, which compiled the collected data from all the HMI applications and performed a series of macro-level analyses of the information collected.  This approach worked fine for many continuous process applications that didn’t require a great deal of real-time data analysis.  But as systems grew more sophisticated and manufacturers’ productivity and efficiency requirements became more complex, this model was no longer sufficient in many cases.

As a result, HMI systems that also provided SCADA functionality were at an extreme advantage over those that focused exclusively on graphics packages – in effect, providing the HMI only.  As high speed systems quickly grew to require much of the SCADA-level calculation and analysis capabilities on the plant floor instead of through a remote engine, mere HMIs were no longer sufficient.

Today, that model certainly holds true.  To be most effective, HMI and SCADA must be available on the same system to perform analysis and calculations at the device level, in order to maximize the speed, accuracy and scalability required by a real-time data-driven production environment. 

There are four key reasons for this shift.

1. Plant floor operators need access to more detailed information than in the past.  Instead of simply recording when  and for how long a system went down, they need to have significant insight into why it happened in order to install safeguards to protect future performance.

2. Operators need greater access to information across the enterprise.  Operators can no longer focus exclusively on one particular area of the plant.  With fewer personnel doing a greater share of the work, this simply isn’t possible.  They need access to other areas of the plant, related equipment and other contributing variables that can affect the overall performance of the production line.

3. Feedback is needed NOW.  Gone are the days when an operator could wait until the end of a day or even the end of a shift to know if a line or piece of equipment was underperforming.  In order to maintain today’s production requirements, they must know immediately if a breakdown in productivity is occurring, where it’s occurring, and how significant of a problem it is.

4. Greater functionality is needed.  By leveraging a SCADA’s connectivity to higher level applications, users can take advantage of inherent compatibility with historian and change management tools, as well as the higher level Production Management and ERP applications needed at the business level.

In this way, today’s SCADA users are looking for far more than Supervisory Control and Data Acquisition.  They need a Supervisory Calculation and Data Analysis tool that can empower them with the extended real-time capabilities that have literally redefined this standard industry term.