November 2019

Special Focus: Instrumentation and Automation

Building industrial networks to serve IIoT and digitalization

Two of the terms growing in popularity over the past few years are “digital native” and “digital immigrant.” Natives are those individuals young enough to have known computers and the internet since childhood. For them, such technologies have always existed. Immigrants, either through age or circumstance, had no exposure until later in life. Hopefully, for them, such technologies are a welcome addition to work and life, but they can remember times when most activities were more manual, local and isolated.

Logue, C., Emerson Automation Solutions

Two of the terms growing in popularity over the past few years are “digital native” and “digital immigrant.” Natives are those individuals young enough to have known computers and the internet since childhood. For them, such technologies have always existed. Immigrants, either through age or circumstance, had no exposure until later in life. Hopefully, for them, such technologies are a welcome addition to work and life, but they can remember times when most activities were more manual, local and isolated.

For people working in processing industries, there has been a different experiential division related to computer technology, and this one is more complicated.

Most engineers and technicians working in refineries have experience with distributed control systems (DCSs)—the automation systems running their plants and process units. Those around retirement age can probably remember back to the early 1980s when these systems were still new, but it was clear that computer-based technology was the best way to run these facilities.

Simultaneously, in the early 1980s, the concept of information technology (IT) was filtering into our minds as computer systems were moving more into offices with the introduction of the personal computer (PC). Over time, this involved PCs replacing mainframes and minicomputers, with desktop units turning up in totally new places.

The world of the plant and the world of the office grew in different directions with specialized and proprietary hardware and software running the plants, while increasingly standardized hardware and software ran offices and corporate networks. The former was eventually characterized as operations technology (OT)—with its distinct practices and requirements—to distinguish it from IT.

OT and IT continued on parallel and separate courses until two major changes began to happen. First, DCS builders found that IT platforms had advanced enough in power, reliability and versatility to support many DCS needs. They realized it was no longer necessary to create and manufacture so much proprietary hardware and software, especially for human machine interface (HMI) platforms. Second, refinery management started gathering manufacturing data from individual plants and process units. IT departments were then building connections to the OT systems to extract data, and OT was no longer isolated.

Where does that leave us now? Both worlds have been populated with their respective digital natives, but it is a different understanding of what “digital” means, with different languages and cultures. The trends that started decades ago are continuing, so the separation has been breaking down as IT has moved increasingly into the OT world and has replaced the old proprietary platforms. OT has no practical choice but to accept the change and learn the new language. The cultural differences are not as easy to resolve, but they can be smoothed over as IT people learn what OT is about, particularly the special needs of manufacturing. Digitalization programs require extensive blending of IT and OT, and it is often difficult to determine the dividing line.

Fig. 1. IT and OT networks can be connected on many levels, often making the differences between them difficult to distinguish.
Fig. 1. IT and OT networks can be connected on many levels, often making the differences between them difficult to distinguish.

Wired and wireless Ethernet networks are part and parcel of plant infrastructure and are becoming increasingly pervasive. Nonetheless, OT is still alive and well at the lower levels of plant networks (FIG. 1). Individual field devices (such as instrumentation and valve actuators) still communicate using purpose-designed protocols rather than Ethernet. Most field devices are wired, but growing numbers are communicating via an industrial wireless protocol, such as WirelessHART. Digitalization projects must bridge this persistent hardware and software connectivity gap, but the mechanisms for doing so are getting better all the time, with wireless Ethernet (e.g., WiFi) being a critical tool.

A typical plant task, then and now

Many years ago, technicians who were sent to replace general-purpose valve actuators in operating refinery units had several tasks. They would have to hunt to find the specific valve, verify its tag number, and engage with the control room operators while doing the mechanical work and electrical connections. This back-and-forth would be done via walkie-talkie as the test actions were carried out. The technician would ask the operators to ensure that the data from the new actuator appeared correctly on the screens, and then to send commands to the valve via the control system to verify correct function from that direction.

Under ideal conditions, this practice typically worked well. Provided the operators were not busy with something else, like an upset or product grade change, they could give the well-trained technician enough attention to work through the checklist of function verifications. Conversely, many things can go wrong with such interactions, or they can simply drag out and consume too much time. Progress slows if the control room is trying to juggle multiple distractions, or if the technician encounters a problem and must ask for help with a configuration setting or unclear wiring termination.

Fig. 2. Ruggedized computer hardware can be used in plant environments, with some units certified for hazardous locations.
Fig. 2. Ruggedized computer hardware can be used in plant environments, with some units certified for hazardous locations.

Let us consider the same task, this time approached using the more sophisticated digital technology that is available now. Our technician has a ruggedized tablet (FIG. 2) communicating over the plant WiFi network. The work order appears on the screen, including the relevant valve actuator tag number, along with detailed product information. Reading a barcode on the actuator verifies the correct unit, and the technician can send a message back to the control room warning operators that the device is switching to manual mode, although the valve will stay in its present position. All the necessary instructions and parameters for installing and configuring the actuator are accessible on the tablet.

Communication from the tablet can be established with the actuator via the network whether the actuator is wired or using WirelessHART. All configuration points can be transferred through the network rather than being entered manually by the technician. All the verification tests, from the field end or control room end, can be run from the tablet since it can take on either role. This avoids involving the control room, although the operators can see what is happening, if necessary, and they can even verify the technician’s location from the control room, thanks to location awareness technologies.

When the installation and testing are completed, the technician closes out the task on the tablet to automatically complete the work order. Then, the technician restores the actuator view back to the control room, and lets the operators know it is back online and in automatic mode. The actuator replacement is completed, and the operators were barely aware of the situation since they had little to do with the procedure, other than to monitor the technician’s activity at a high level.

Walking the rounds

The technician may also have responsibilities to perform plant rounds of one or more units. In the past, this would mean carrying a clipboard and checking a pressure gauge reading and/or oil level, and then noting the information on a sheet that would be turned in to the control room or maintenance office.

Those functions are now likely performed by instruments, but many plant managers still like to have human beings walking around the facility, using their eyes, ears and even noses to notice things that might escape the instrumentation. Manual rounds may require being out in bad weather or potentially hazardous areas of the plant, so they are not always a popular assignment, but digitalization projects can help improve low-tech tasks.

Fig. 3. Finding critical information on the spot can be a huge time saver during commissioning, troubleshooting or other activities.
Fig. 3. Finding critical information on the spot can be a huge time saver during commissioning, troubleshooting or other activities.

The traditional clipboard is replaced by the ruggedized tablet, complete with instructions related to anything special to watch for on the shift (FIG. 3). A note section may display items such as “operators complained that valve 210B was sticking, so make sure that the actuator mounting is tight. PT-48 seems sluggish, so check the impulse lines.”

The technician can communicate back to the control room from anywhere via the tablet and can take photos or a video of a piece of equipment for the operators or anybody in the company to see via the corporate network. This is simple because, given the correct authorization, the information is accessible over the company intranet, and possibly over the internet.

If the technician needs technical information on a piece of equipment, it is a simple matter to look for it on the plant’s database or on the original manufacturer’s documentation on the web. If it is necessary to ask for help from a troubleshooter back at the manufacturer, it is a simple task to send photos or a video of the problem for evaluation. The situation may not call for the manufacturer to send a serviceperson, saving time and cost.

Safety is always an important consideration when people are moving around a unit, particularly when rounds necessitate going into particularly hazardous areas. Plant networks have provisions for emergency “worker down” calls, but they can also add location awareness functions, triangulating a radio source to a very accurate position in three dimensions.

Improved coverage makes it practical

The scenarios mentioned are nothing new, but not all refineries are using them to the extent suggested. Various vendors have been talking about mobile workers, personnel location and such capabilities for several years. At present, the difference is improved network coverage and bandwidth. Think about someone owning a smartphone 10 yr ago. This early smartphone was web-enabled, but trying to reach a website or download a document in an airport or on the street was a catch-as-catch-can situation. Watching the ever-downloading spinning wheel was a typical experience, and many users simply gave up as often as not. Why? Users wanted more performance than they could get. Network coverage in most areas was too thin and bandwidth too low to meet expectations.

Many in-plant WiFi networks had, and may still have, the same problem. Theoretically, there was coverage, but moving any amount of data was an iffy proposition. Many companies implementing networks also underestimated the usage they would have to accommodate and did not include enough infrastructure for full coverage or enough bandwidth. In the last few years, both public and plant network hardware have advanced enormously in coverage and bandwidth handling capability. Let us concentrate on in-plant networks.

At present, an industrial-grade WiFi router can support more protocols and more devices, and can operate in more challenging conditions than a router from just a few years ago (TABLE 1), with more modular designs that are easier to deploy (FIG. 4). Such routers support high-bandwidth WiFi networks, and can work in conjunction with WirelessHART field devices, using WiFi as the backhaul network.

Fig. 4. Routers can handle more devices while tolerating extreme plant environments. Modular construction makes them easier to configure and deploy.
Fig. 4. Routers can handle more devices while tolerating extreme plant environments. Modular construction makes them easier to configure and deploy.

A wireless router can also serve as a gateway for WirelessHART and ISA100 Wireless devices, if both are deployed. Wireless instruments and actuators still communicate using their dedicated protocols, but communication with host systems, such as a DCS or an asset management system, can be either wired or via WiFi—in both cases, typically using an Ethernet protocol.

This blending of WiFi and WirelessHART enables the realization of Industrial Internet of Things (IIoT) concepts in which IT and OT are integrated as never before. These networks encompass wireless field devices, smart sensors, asset management solutions and analytics that are able to deliver digital transformation.

Making it happen to the fullest extent requires many WiFi wireless access points (WAPs) using high-bandwidth technology. At the scale of a typical refinery, this could mean anywhere from 100 WiFi WAPs–400 WiFi WAPs to achieve complete and seamless coverage. When implemented, access is available anywhere, allowing the capabilities of mobile workers and rapid wireless instrumentation deployment to be realized.

Routers simplify deployment planning, thanks to their modular design. If it is necessary to add a WirelessHART or an ISA100 gateway to a given unit, this can be done easily. Smart antennas for wireless instrumentation can improve range, while restricting coverage to inside the fence line. Most routers are Class 1/Division 2 rated, and antennas are Class 1/Division 1 for extension into hazardous areas.

Some users are suspicious of wireless networks believing they add a larger attack surface for cyber criminals. Fortunately, networks and their current-design hardware use very strong defensive mechanisms. For example, WirelessHART is protected by 128-bit AES encryption at the network/transport layer and a two-factor network joining mechanism. Design of WiFi networks and interfaces with other systems will normally be left to the IT group, so it can use the latest security tools and practices to avoid vulnerabilities at data hand-off points. Companies that routinely update routers and other network equipment avoid the problems resulting from keeping multi-generational hardware in place, which forces the use of older security techniques.

User advances

How are companies putting these technologies to work? Companies that have implemented improvement programs with digitization point to a variety of areas where they have seen major advances:

  • Improved WiFi and WirelessHART infrastructure with higher data transfer rates and reliability
  • Improved personnel safety with location and mustering capabilities
  • More detailed energy consumption data, resulting in conservation and cost savings through expanded monitoring and data analysis
  • Improved manufacturing asset reliability and availability
  • Increased productivity resulting from quick responses to abnormal conditions using mobile worker tools
  • Faster execution of loop checks during commissioning and startup, which can lead to millions of dollars in revenue, thanks to additional uptime
  • Higher plant availability through a reduction in unexpected shutdowns.

These are all elements of digitalization, and there are many more possibilities, as clever and creative people discover new ideas. When wireless infrastructure performs to the extent that users do not have to think about it, whether at the device or corporate network level, great progress can be made. When vendors and users can point to a global installed base with wireless networks, smart sensors and asset management solutions, this is the realization of a digitalization vision. HP

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