Creating Agile Process Control | Automation.com

Creating Agile Process Control

Creating Agile Process Control

By Josh Eastburn, Director of Technical Marketing, Opto 22

Process automation is a relatively imprecise term describing how industrial systems are monitored and controlled. These systems might consist of machines, packaged skids, or larger and more distributed production processes. Discrete control (on/off or open/closed) is often necessary in process control, and some analog control of pressures, temperatures, flows and the like is normally required as well. Designers choose process automation elements from a variety of sensor, input/output module, controller and operator interface options.

Regardless of the elements chosen, the primary goal is a reliable, accurate, and ultimately valuable operation. But although the main goal is a stable process, designers shouldn’t ignore other opportunities. More than ever, process automation professionals must be ready to take advantage of the extended business improvements possible with the new automation devices and communication technologies available today.

For process control systems, these improved hardware and software options can ease design activities, make system operations more effective and offer new methods for end users to access and monitor equipment. Here are some of the ways that standard process automation products and practices are transitioning to encourage more agile and capable systems.

 

Make the Most of Smart Devices

Smart devices located in the field have many names and take various forms. They can be individual intelligent sensors or larger packaged systems. They might communicate via a traditional industrial fieldbus or new IT-based protocol. Many of these new devices use wireless technologies and are battery operated. Collectively, these smart devices used in an automation context are often referred to as the “things” in the industrial internet of things (IIoT).

These IIoT devices are interesting for at least two main reasons—reasons that should prompt designers to adopt IIoT methods into their process automation designs.

The first reason is the relative economy of using IIoT devices. Individual sensors are usually low-priced compared to more conventional instruments, and many intelligent packaged systems already offer an I/O or communications capability. The ultimate driver is installed cost. Because so many IIoT devices support wireless, battery-powered operation, they can be installed for a fraction of the price of conventional instruments.

The second reason is that IIoT devices usually offer far more than just the single process variable typical with most traditional instrumentation. Contemporary smart devices commonly support browser-based configuration, multiple data points and extended information for diagnostics. For example, the signal input, linearization, and scaling for each channel of an analog input module might be configured differently, which offers potentially lower cost and greater density. Similarly, the calibration and maintenance data for a control valve might be retrievable from the device itself, which improves auditability and reduces administrative overhead.

Core process automation I/O points will continue to use established instrumentation methods for critical monitoring and control. But eventually, this essential I/O may rely heavily on IIoT methods. For now, designers should make themselves aware of newer IIoT devices and other smart equipment and explore the new capabilities they offer.

 

Simplify Connections with Flexible Interfacing

Integrating data and processes between systems and equipment from different automation manufacturers is traditionally difficult—and increasingly required.

Some process automation systems are widely distributed within a facility and automated by just a few large programmable logic controllers (PLCs). But even these systems usually need to interface with some individual IIoT devices or smaller packaged systems such as utility skids, fillers and packaging machines. Other process automation systems may be assembled almost entirely from packaged subsystems.

The challenge is when field devices and subsystems come from many OEMs, with each providing unique functionality and differing control platforms. Integrating these systems can be difficult and require many layers of “middleware” (Figure 1).

Figure 1: Connections between process automation systems and applications can be simplified and IIoT goals achieved by using an EPIC (edge programmable industrial controller) to flatten the architecture.

Modern control system hardware and software helps system designers overcome these challenges by offering a new class of controller: an edge programmable industrial controller (EPIC). EPICs simplify connectivity and integration by collapsing the layers of complexity and flattening the process automation architecture.

EPIC components are true programmable industrial controllers built for installation in the field at the edge, where automation interfaces with the process equipment. In this way they are much like a PLC. However, EPIC components have the advantage of including networking options, plant floor communication protocols and IT protocols. These additional capabilities mean an EPIC can integrate almost any type of intelligent field device into the automation system and up to higher-level applications. The Opto 22 groov EPIC is an example of this type of automation platform.

Designers can use EPICs directly for process control, for connecting to existing PLC process control systems, and for communicating data with company applications and cloud services, if needed.

EPIC components can also be installed in parallel with existing automation, in order to communicate IIoT data to higher-level applications without impacting already operating controls.

Facilitating this effort are communications protocols such as message queuing telemetry transport (MQTT), optimized to securely transport data from the edge up to core systems. MQTT is an ISO standard publish-subscribe messaging protocol, which can efficiently communicate data using wired Ethernet, Wi-Fi, radio or cellular data networks. Often used for remote installations, MQTT is also effective for communicating data among independent systems within a factory setting. The protocol uses report-by-exception and a central broker/server to minimize network traffic.

Edge computing like this, using components that incorporate IT-friendly protocols, helps designers by giving them more connectivity options and simplifying design choices.

 

Achieve the New Standard: Visualization Everywhere

For operational end users, perhaps the most significant and noticeable impact of modern process control systems is improved visualization. Industrial automation has used human-machine interfaces (HMIs) for many years, generally as fixed-in-place dedicated terminals or PCs connected to controllers.

But now, inspired by smartphones and their ability to connect users from just about anywhere, controllers can offer integrated on-board or local touchscreen displays, plus seamless web-based and mobile visualization options.

With these new options, many process automation systems won’t require conventional panel-mount or desktop PC HMIs, unless installed as a form of redundancy. Instead, process controls can be implemented with built-in or mobile HMIs (Figure 2).

Figure 2: Modern process automation systems may not need conventional fixed-in-place HMIs because of the local and mobile visualization options available.

Mobile visualization is empowering in many ways. Startup and commissioning personnel find their testing efficiency increases when they can monitor and command field devices while standing next to them and closely observing their functionality. Most operations personnel are already comfortable with personal mobile devices and thus readily adopt mobile HMIs. And maintenance personnel can troubleshoot system problems faster and more comprehensively with mobile devices.

Being able to see the same HMI on the controller itself, on a PC, or on a mobile device offers the flexibility to use the best visualization device for the situation. For hazardous locations, technicians can keep a safe distance. For remote operations, costs are reduced when operators don’t have to travel to the site. For factory processes, the cost of industrial PCs can be avoided by using the built-in touchscreen or adding a monitor to an EPIC processor.

Benefits can also be realized at higher levels in an organization. Because modern systems offer configurable user accounts with encryption and authentication, specific HMI screens can be created for different users. For example, managers can view high-level dashboards with only the data they need, while operators see a different screen with detailed controls and signal monitoring.

 

Take Process Data to the Next Level

More information available directly from the field controller level can improve process control. Enhanced visualization helps operators better understand how the process is running. But perhaps the greatest long-term value can be found when more data is made available to higher-level systems for historization and analysis.

In the most basic case, users manually review the trend of historized data (Figure 3). Using exported spreadsheets, statistical control methods, and their own experience, process experts identify ways of optimizing operations.

Figure 3: Process automation systems integrated using platforms like Opto 22’s groov EPIC can leverage modern technologies to support data analysis capabilities ranging from basic to advanced.

A more comprehensive method is to employ advanced data analytical software, often running in the cloud, to examine large amounts of historized data and look for more obscure relationships. The ability to gather as many additional data points as possible outside the basic process control I/O is crucial to improve the analysis outcome. Integrating modern IIoT-capable edge computing platforms enables process experts to collect and transmit this data efficiently.

 

Basic Process Automation Can Do Much More

Process automation systems must first and foremost deliver reliable operation. Yet the hardware, software, networking and design methods are now readily available to deliver far greater capability.

Automation designers are finding they can easily incorporate IIoT devices and other smart equipment, either directly into the control system or in parallel for data gathering.  s a result, new options make connections simpler and more flexible, which in turn supports visualization anywhere and the ability to perform useful analysis. Together, the result is more agile and valuable process automation.

About the Author 

After 12 years as an automation engineer working in the semiconductor, petrochemical, food and beverage, and life sciences industries, Josh Eastburn works with the engineers at Opto 22 to understand the needs of tomorrow's customers. He is a contributing writer at blog.opto22.com.

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