Using connectivity software to integrate the IoT with existing systems

As the number of Internet of Things-enabled devices grows, connectivity becomes the biggest hurdle. Open platform communications (OPC) and data distribution service (DDS) provide two approaches to bridge the communication gap by reducing the complexity required to integrate with new devices.


The difficulties of integrating the Internet of Things (IoT) with existing systems are similar to radio and television. Both radio and television use radio waves to transmit their signals, with hardware on either side to encode and decode the signals into audio and images. While the overall concept is the same, the results are very different.

This is analogous to configuring a device from one manufacturer that uses one type of communication protocol to communicate with a system from a different manufacturer that uses a different protocol. Unless specific translations are present, the two devices won't be able to effectively communicate with one another. This is where connectivity software like open platform communications (OPC) and data distribution service (DDS) comes into play. 

Reducing complexity

While their technical details differ, OPC and DDS are similar in their ultimate goal, which is making it simple to connect devices that use any number of protocols by implementing a standard set software interface. This not only simplifies the lives of industrial automation companies that supply control system hardware and software by building support for these protocols, but also makes it easy for new device and instrumentation companies to integrate with existing systems that were developed prior to the concept of the IoT.

One example of this type of integration between new technology and existing systems is the concept of geo-fencing and beacons. Geo-fencing is where a software system uses specified locations on a map to track when people are in a particular area; beacons are similar, using hardware combined with location-aware devices to track how far away people are from the beacon itself. This technology has been widely used in consumer retail applications to send customers relevant coupons or notifications when they are near a store or restaurant. This concept can be applied to the industrial world for safety and/or emergency alert systems.

For example, with a geo-fencing system in an industrial facility combined with location tracking of operators, alerts can be sent to the control room's human-machine interface (HMI) when operators enter a specific area of the plant. In the event of an emergency, it is easy to track down the exact location of everyone in the facility using this information. This data can also be integrated with the control system when using mobile devices for data collection. As an operator moves throughout the facility, his or her device can automatically load the correct data entry screens to collect readings as the operator moves to different process areas.

Using the geo-fencing example, integrating a technology not built with the industrial world in mind can require a huge amount of effort, requiring development work and testing with a large number of systems architectures. Instead, if the geo-fencing vendor designs its system to integrate with the control systems using OPC or DDS it only needs to develop one or two integrations to open itself up to communicate with any control system that uses OPC or DDS. This can immediately increase a vendor's potential market share without any additional work.

Safety is a number one priority

While OPC and DDS are similar in theory, they have different technical backgrounds. OPC is a client-server-based architecture where the OPC server communicates with clients, typically industrial control systems. DDS has a decentralized architecture with devices using the protocol and creating a type of network to distribute messages in a peer-to-peer fashion.

OPC has a long history of being developed for and used in industry, with many protocols offered by a variety of OPC solutions, along with database integrations, serial device communications, and hooks for Web-based system integrations. DDS, on the other hand, was initially developed from more IT-centric applications simplifying communication across networks and is moving into industry as broader scope technologies are adopted into control system architectures.

Both OPC and DDS act as middleware between end devices or overall systems and other systems and enable standardized communication configurations to transfer data to where it needs to go. The choice between the two will likely be dictated by the systems and end devices in place, and what integrations are offered by each of the solutions. A final system design will likely include both as the IoT becomes more and more prevalent in manufacturing.

Integration benefits

OPC and DDS can be great tools to increase the overall capabilities of industrial control systems (ICSs). They can help integrate new devices into a facility, providing more information and context about a process and enabling operators and staff to make more informed decisions about how to operate.

The main questions to ask are what information would be most useful to have, where does that information come from, and what is the easiest way to get it to where it needs to go? This might mean using some combination of standard protocols within a control system and both OPC and DDS to integrate nonstandard devices.

One of the main benefits of the IoT is the ability to integrate with any number of new technologies, some which have not yet been imagined. Making it easier to integrate with the industrial world will speed up the return on investment (ROI) in this technology and benefit manufacturers everywhere.

Alex Marcy, P.E., is the owner and President of Corso Systems, a system integration firm based in Chicago, Ill. Edited by Chris Vavra, production editor, CFE Media, Control Engineering,


Key concepts

OPC and DDS are designed to connect devices that use any number of protocols by implementing a standard set software interface.

OPC is a client-server-based architecture whereas DDS has a decentralized architecture that distributes messages in a peer-to-peer fashion.

Easier integration with the industrial world will benefit manufacturers everywhere and speed up the return on investment. 

Consider this

What other technologies or concepts could be used to integrate with the IoT?

ONLINE extra

See additional stories from Alex Marcy linked below.

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