IIoT at the IO level
The Industrial Internet of Things (IIoT, also designated I2oT) has been getting much discussion lately, as if it has burst on the scene fully formed and ready for immediate use. A closer examination shows that, at least where we are in mid-2015, much of what is being billed as IIoT is either not industrial or not Internet.
Common machine-to-machine (M2M) communication techniques that have been in use for some years are now being rebranded as IIoT whether any Internet protocol is involved or not. This is causing some confusion to say the least.
Four IIoT misconceptions
Common misconceptions about the IIoT include:
- All process control functions will move to the cloud.
- Any field device will be able to communicate with any other field device anywhere in the world.
- Enormous amounts of new data will be created.
- Everything will be wireless.
These misconceptions tend to emerge from much of the current discussion because it fixates on the benefits expected to emerge from adoption rather than understanding the technology itself. It’s more fun to talk about the benefits of "big data" than to pull apart the communication stacks. Once the underlying concepts are better in hand, the benefits will be easier to understand. Rather than talking about what IIoT might be able to do, it is more useful to discuss what IIoT is and how it will work. In that way it will be easier to recognize the real thing and possibly reduce the level of hype.
First and foremost, the IIoT is infrastructure—it enables and supports communication, and that is the extent of IIoT capabilities. Maybe that doesn’t sound very exciting, but don’t underestimate what IIoT implies. New networks will be faster and will offer more sophisticated connectivity.
What IIoT isn’t
The Internet part of IIoT is the use of IPv4 or IPv6 for its addressing, so communication that doesn’t use Internet Protocol (IP) is really not IIoT. The IIoT does not create data nor will it change the way we deploy instrumentation in a typical process manufacturing environment. (Much, if not all, of the data promised is available today using conventional technologies, but users aren’t collecting it for a variety of reasons. It remains to be seen whether or not new infrastructure will somehow make data more compelling.)
Implementing the IIoT will have a major impact on the way control systems communicate with field devices, which is, of course, the basic input/output (I/O) function. If IIoT succeeds in making device-level communication easier and less expensive, users will likely find opportunities to deploy a larger number of sensors (some of which might be wireless), though field instruments will still have to pass the same evaluations for safety and robust construction. All the other costs of deploying a new sensor still will apply, such as adding it to plant databases, adding it to control room human-machine interfaces (HMIs), process unit piping and instrumentation diagrams (P&ID), etc. A consumer-grade, smart, Internet-enabled thermostat will not be attached to the side of a refinery distillation column.
In the May 2013 issue of Control Engineering, Herman Storey offered some thoughts on the technical side of where the IIoT was heading and what would be needed to make it practical and effective. Since then, the discussion has certainly intensified, although actual technical progress has been limited.
The updated information presented here revisits the topic, offers an update, and discusses how IIoT will be used at the device level. Below, Storey wrote his comments using a question-and-answer format (in education, known as a catechism). Since the IIoT has become almost a religion to some, this approach seems particularly appropriate.
Learn more about five ways in which the IIoT is new and six reasons why it will be slow to catch on.
IIoT insights from Herman Storey
What is the IIoT?
IIoT is an open system for interconnecting intelligent devices, systems, and HMIs. It will utilize technology developed along with Internet technology and cellular-phone technology to provide faster, more open, more mobile, and more user-friendly interconnection and communication. It will primarily support existing functions and user interfaces, but will also provide infrastructure that supports new functions and user interfaces.
Where will it be used in industrial control systems?
IIoT will primarily impact I/O subsystems in industrial control systems. The multi-level architecture will segregate functions using zones and conduits (as defined in IEC 62443), which is necessary and will be retained in IIoT. However, improvements in digital communication at the bottom of this structure can provide significant benefits.
Will every device have its own IP address?
The commercial IIoT is promising that every device will have an IP address. For example, you will be able to access your smart toaster from anywhere in the world. The thought that every field device in a process plant needs to be accessible from anywhere is irrational. Any situation where one device truly needs to talk to another is probably already happening and should remain as such.
Where will all this "big data" come from?
The IIoT cannot create data in and of itself. However, it will be very good at transferring data generated by smart devices to a historian or to the cloud. One of the promises of the IIoT is that it can help move large amounts of data to and from cloud-based applications that can analyze it and turn it into more useful information. The practicality of this approach for day-to-day operations is still being proven and may change over time.
What will stay the same as today?
Changing to IIoT will not change the nature of how we operate a process plant. All current control system functions will continue to be performed on-site with the new infrastructure, and the existing functions will still be served well by existing applications. We will still measure and control flow, level, pressure, and temperature, and the existing user interfaces used to configure and troubleshoot these functions will continue to be used. The kind of real-time control necessary to run a refinery or chemical processing plant safely and efficiently is impossible without an on-site control system, so that kind of operation will not be moved to the cloud.
What is new or different about IIoT?
1. Physical media—Addressing or routing of messages, synchronization and scheduling, cyber security, mobility, and location of functions will all be affected. At the physical (PHY/MAC) communication stack layer, our industrial facilities are full of relics conceived during the vacuum-tube era. These communication relics are slow and often are tightly bound to one application layer without security and the ability to route, switch, or share media. They will need to be replaced.
2. Internet Protocol—IIoT will use Internet Protocol (IPv4 or IPv6) to provide modern routable and switchable messaging. IIoT will be able to use any physical layer that is optimum for the needs of the installation and will be able to substitute or convert media with a simple bridge or router. Some newer media (like DSL with power over twisted pair) may show up in field networks to provide higher speed than some of the obsolete networks, but these newer networks will be mixed with wireless (IEEE 802.11 and 802.15.4), wired (IEEE 802.3), and fiber media. No single medium will satisfy all installations. Many older protocols have already been converted to run with IP and newer media. This trend will continue and expand.
3. Synchronization and scheduling of messages—This capability is being improved by a cooperative and important joint effort between IEEE and the Internet Engineering Task Force (IETF) called deterministic Ethernet (DetNet). Time synchronization is being improved to the sub-microsecond level by improvements in IEEE 1588. This along with dedicated buffering and message delivery will provide significant improvements in high-speed control applications. This effort will be applied to wired and wireless applications. AVnu will provide interoperability profiles and testing for DetNet.
4. Cyber security—These new technologies will change the attack surface for field networks and demand different defensive strategies. Both devices and users will require authentication and authorization for networks and for applications. Networks will have to be managed, and user-friendliness of network management tools will make or break cyber security. ISA100.20 will provide models, terminology, and eventually standards for common network management.
5. Mobility—Our current offering of mobile devices will need enhancements. In reality, the only truly mobile devices we have now are our cell phones. Users and devices need better mobility support and continuous connection while in motion. In fact, all of the five mobility classes outlined in ISA100.20 need to be supported in industrial networks.
In the good old days, the only way to access a device was to reach out and touch it. This model worked for many years and was a practical substitute for cyber security, but it no longer serves the needs of today. Data needs to move to and from the engineer, instead of the engineer moving to and from the data.
Some functions like control and history collection need to be close to I/O infrastructure for performance reasons. However, operator and engineering functions can often be remote. Maintenance support will require providing both local and remote support. Mobility is needed for all local and remote functions. All functions will not move to cloud-based hosts. Some functions could move, but it is not clear that the advantages will outweigh the complexity that would come with this move. There will be experiments, with successes and failures, using cloud-based functions. The important distinction is that remote access and cloud-based access are different concepts. Remote access is required, and cloud-based access is an option. IIoT will enable both.
What are some of the barriers and enablers for implementation?
There is no question the IIoT is a disruptive technology, and, current hype notwithstanding, adoption will be very slow among users and vendors for six reasons:
- Large installed base of devices and host systems
- Vendor product migration issues
- Openness of eroding vendor profit margins
- Cost and complexity for users
- New support skills for vendors and users
- General inertia, along with a variety of other technical factors.
IIoT will not have a significant effect on the installed cost of I/O subsystems, so it can’t be sold as a money saver against traditional methods. It will probably have a negative effect on profit margins for vendors supplying these systems. The disappearance of traditional I/O gear racks and marshaling cabinets will be a lost opportunity for vendors and integrators. However, these people will still need to make a profit if they are to be able to serve customers’ needs. Efforts to find new sources will likely intensify turf wars between host system vendors and device vendors. Provision of services may fill the void, but all suppliers will have to work to avoid interoperability problems.
IIoT systems and devices will have to support legacy networks for decades to come. History has shown that the industrial-installed base will not change quickly. Digital has never fully replaced analog in plants, and it shows no sign of doing so in the near future. Migration will cost money and require new skills for users, engineering firms, system integrators, and vendors.
A lot of the inherent complexity of IIoT can be hidden by clever system design and vendor cooperation via consortia, but experience says the first products that hit the market will be half-developed. The early phase of this transition will not be for the timid.
– Peter Welander, contributing content specialist, CFE Media, Control Engineering, firstname.lastname@example.org; Herman Storey is chief technology officer of Herman Storey Consulting LLC. He is co-chair of the ISA100 and ISA108 committees.
- Much IIoT-related discussion does not consider the technical aspects of the technology.
- The IIoT will cause many disruptions to traditional practices, which is causing different organizations to spin the discussion in specific directions.
Also see a webcast series on the topic at www.controleng.com/webcasts.
How can IIoT help you transfer smart-device data to a historian or to the cloud for better analysis and for more real-time benefits?