Benefit from IIoT without IPv6

Kevin Ashton, the father of IoT, tells the story of the Internet of Things (IoT) in his book How to fly a horse – the secret history of creation, invention, and discovery: While at Procter & Gamble he was working on a problem: stores ran out of a popular lipstick. Every other store was out of stock and the storekeeper didn’t even know because their system was not up to date; insufficient information. The only way to know what was on a shelf was to go look. Store workers did not have time to check the shelves every day, then manually type in the data, so the store's system was approximate. Shoppers were first to discover that the lipstick was out of stock; not the shopkeepers. The sale was lost. A small issue, but a symptom of a larger problem: computers are brains without senses. To solve the problem he put a radio chip into a lipstick and an antenna into a shelf. The chip connected to the Internet to store the data. He gave it the name "the Internet of Things."

I met Kevin Ashton at the NASSCOM Design and Engineering 2016 summit where we were speaking. Before my session (video) I asked Kevin; do ‘things’ need an IP address? He replied; “No, absolutely not”. That is, the type of industrial sensors based on FOUNDATION fieldbus and WirelessHART already used in plants, can be, and already are, used for IIoT applications as well. An IPv6 address is not a must. So how does all of this relate to industry applications? Here are my personal thoughts:

Manual Data Collection in Plants

In a plant the symptoms are different but the problem the same: for instance, fans fail unexpectedly. Fans have vibration issues but the reliability manager may not even know because the condition is not up to date in the system; insufficient information. The only way to know the condition of the fan is to go check with a portable tester. Maintenance workers do not have time to inspect every piece of equipment hourly or even daily, then manually type in the data. It is usually done monthly or weekly so the plant's maintenance system is impaired. Operators are often first to discover that the fan has tripped; not the maintenance engineers; this results in process downtime. The problem is largely the same: Computerized Maintenance Management Systems (CMMS) are brains without senses. To solve this, plants are now putting more sensors on equipment, digitally networked, often wireless, sending the data through the Internet to software analyzing the condition and performance. This is what we call Industrial IoT.

Uniquely Addressing Billions of Devices

So how do you deploy millions of networks, billions of sensors, worth trillions of dollars (I always hear Carl Sagan’s voice in my head when I read these IoT numbers: mullion, bullion, trullion) without IPv6?

International standard industrial protocols like IEC 61784-1 (FOUNDAITON fieldbus, PROFIBUS, and DeviceNet etc.) as well as IEC 62591 (WirelessHART) used in industrial applications use only 1 or 2 bytes for the address. One might be mislead to believe a single byte limits the number of devices to 255 or less, but this is not the case. Only the number of devices per sensor network has this limit. It is already standard practice for plants to have multiple sensor networks that connect to a common Ethernet backbone and optionally the Internet through a gateway or controller which has an IP address. The gateway automatically performs the translation of network addresses to ensure one sensor out of billions of underlying sensors on the Internet can be correctly addressed from anywhere in the plant or in the world. This way plants already have thousands of devices, and the same way there can be billions of sensors on the Internet even without IPv6 in the sensor itself as long as the gateway has an IP address.

A key protocol feature to ensure sensors can easily be uniquely addressed among billions is for each device to have a unique identifier. Both FOUNDATION fieldbus and WirelessHART devices have such unique identifiers so these two protocols are ideal for Industrial IoT and are already widely used in IIoT based applications.

Another key protocol feature to ensure easy integration of all the data in the device is preservation of application protocol. That is, the application protocol used on the local sensor network shall match that used with IP over Ethernet and across the Internet. For instance, in the case of FOUNDATION fieldbus this would be FF-HSE, and for WirelessHART this would be HART-IP. This way no data mapping is required making deployment very easy.

The $50 Industrial Switch?

So would there be any benefit of every sensor having an IPv6 address? Sure, there are potential pros, but also cons. One potential benefit of IPv6 is that a gateway is not required for protocol translation. A simple switch or router is sufficient since the communication passes straight through. For now they are still very expensive. Note that eliminating the gateway requires all devices to have native support for one or more IP-based application protocols like PROFINET, EtherNet/IP, FF-HSE, HART-IP, or Modbus/TCP etc. For IPv6 sensors this is frequently not the case. Typically, sensors using IPv6 use application protocols different from those used over Ethernet. If the native protocol of the device is not one of the standard industrial protocols used over Ethernet media, a gateway is still required and a main benefit of IPv6 is missed. The prices for industrial Ethernet switches could in the future become very competitive if the volume goes up. It could perhaps approach commercial grade switch prices of $50 depending on the country of origin?

Another potential benefit is that IPv6 device may allow basic setup and diagnostics using a web browser. Note that this requires the device to have an embedded web server. For IPv6 sensors this is often not the case. Typically, sensors using IPv6 do not have an embedded web server, especially wireless sensors, so a main benefit of IPv6 is missed. On a separate note, through a web browser the user interface of each device type will be completely different because each device vendor designs their user interface pages differently. There would be no consistency between the many device types found in a plant. Offline configuration download, parameter reconciliation, templates, and centralized audit trail etc. would not be supported by a web interface so it is no substitute to configuration and diagnostics based on DD files. Web server interface and DD interface are complementary. I’m looking forward to more devices with web servers.

Multiple application protocols are possible over IPv6 which has potential benefits. However, it is important the industrial Ethernet application protocols are used natively, not tunneled as a payload of another protocol. If tunneling was to be used, the other devices and applications would also have to support the tunneling protocol, which is generally not the case. Just using the native protocol would not be sufficient thus severely limiting the types of devices and apps that could be used in the applications. Wireless gateways already support multiple application protocols including OPC.

Note that such benefits of IPv6 are potentials. Typically the sensors based on IPv6 and devices using IPv6 today do not support such features.

Ethernet in its present form is not suitable for field instruments due to the need for two-wire operation, hazardous area bus power, and long distance. The Advanced Physical Layer (APL) is currently being developed to solve this problem. APL will combine the high speed and multi-protocol capability of Ethernet with the two-wire operation, hazardous area bus power, and long distance of fieldbus – an “Etherbus” if you will. This is an exciting prospect. Plants built on fieldbus cabling will be able to easily migrate to APL.

NASSCOM Panel Discussion

In the panel discussion we talked about digital disruption and digital transformation adopting connected service business models based on IIoT instead of buying products or relying on manual data collection services. We went on to discuss pay-per-use, per "thing", per tag, and paying for the information on a long term contract for connected services based on the IIoT as opposed to traditional outright purchase in order for plants to have fewer assets on the books - an OpEx model instead of a CapEx model. With this new service model the service providers take responsibility for the IIoT system and also have a pool of experts to support the plants. Cyber security was discussed as well, including use of completely separate systems or data diode.

See the “Digital Disruption & Evolving Business Models” panel discussion in this video:

https://www.youtube.com/watch?v=1o15zRKcjTQ

Your competitor on the other side of the planet may already have begun. Well, that’s my personal opinion. If you are interested in how the digital ecosystem is transforming process automation click “Follow” by my photo to not miss future updates. Click “Like” if you found this useful to you and share it with others if you think it would be useful to them.