Motion control standards drive IIoT

Among the most important standards for industrial motion control are open networking standards for interoperable communications, but don’t overlook the importance of standard naming conventions to ease system integration and promote Industrial Internet of Things and similar initiatives.

By Daniel Repp, Lenze August 1, 2018

In a more connected world, machine builders and end users are finding that the digital part of "intelligent" machines is increasingly more complex and challenging to handle. Industry trends focus on topics like modular connected machines, Industrial Internet of Things (IIoT), plug-and-produce, digital twins, digital factory, and others. The development of motion control applications, as well as the industry itself, is changing rapidly.

To be successful in the quickly evolving future of machine building, and meet the growing expectations of manufacturers, original equipment manufacturers (OEMs) face challenges of standardized communication and interoperability.

End users are buying machines from different machine manufacturers and therefore dealing with different controls platforms, different field buses, and related industrial networking issues. Since all these machines need to be connected to each other to build a machine line, they also should be connected to the cloud.

When a company buys a machine from OEM A and another machine from OEM B, the expectation is that the machines should easily talk to each other-without requiring a lot of engineering to make communication possible. For the end users and machine builders, smart industrial networking leads to an efficient and speedy implementation and facilitates data-based operational optimizations.

Motion control standards, protocols to watch

The following organizations are those making the most impact when it comes to enabling IIoT advancements. The latest developments in open application programming interfaces (APIs) are worthy of attention, including the following standards and protocols that advance interoperability.

OPC UA and TSN

Any machine builder or OEM implementing a cloud-based solution will quickly run across the Open Platform Communications (OPC) Foundation and its Unified Architecture (UA) specification. The OPC UA was released in 2008 as scalable, open-platform technology that would enable better security and data modeling as the manufacturing industry began to explore more service-oriented architectures.

As the amount of data generation at the machine level has grown, the network architectures have had to grow and change. The capacity and performance of standard Ethernet, and industrial Ethernet, may not be keeping up. OPC UA Time Sensitive Networking (TSN), released in 2018, offers a vendor-agnostic, communication infrastructure for industrial automation based on an open standard.

OPC UA TSN enables "real-time" (or close to it) communication between disparate machines, controllers, the cloud, and other information technology (IT) solutions. The development of these specifications is creating what likely will be the closest anyone has come to a holistic communication infrastructure-an evolution that will influence the future design and development of motion control machines.

MQTT

While OPC UA TSN is a broad protocol that guides whole systems, message queuing telemetry transport (MQTT) is a more lightweight protocol that allows two applications to talk to each other. MQTT is often implemented in one product. For example, MQTT allows a sensor or a drive to pull information from the product and send it to the cloud.

MQTT is considered a foundational IIoT messaging protocol and, in 2016, was approved and accepted globally as an ISO/IEC Standard (20922). As such, MQTT is often used as an element in the larger systems standards.

OMAC PackML

The Organization for Machine Automation and Control (OMAC) grew from within the industry and is a collection of end-users, OEMs, machine builders, systems integrators, and technology providers. Some of the original OMAC goals were to reduce delivery times, maximize available resources, and increase profitability across the industry while allowing each individual organization to maintain a competitive advantage.

Among core OMAC initiatives is PackML (aka ISA-TR88), a technical standard focused on industrial automation. Originally released in the United States in 2002, PackML simplifies the integration of disparate machines and standardizes hardware-to-software communication by making machine modes, states, and tag naming conventions consistent.

With the latest release of ISA-TR88.00.02, OMAC is helping to advance standardized communication protocols necessary for IIoT enablement by developing a companion specification to OPC UA.

End of one-vendor ecosystems?

Does all this sound the death knell for "all in" engagements where customers buy within a single-vendor ecosystem?

While bigger companies might have the power to establish their own protocols, it doesn’t serve the end customer well. As soon as a machine builder or OEM needs something outside of the system, and there is no open standard, there is a problem. Only a few companies can supply everything.

When it comes to motion control systems and services in the IIoT age, leading machine builders, OEMs and manufacturers seek hardware and software that perform and efficiently deliver comprehensive data to power remote and predictive maintenance, downtime and condition monitoring, performance visualization, and digital asset management.

Collaboration through open industry standards and protocols enables full cloud connectivity and a complete communication network that unlocks the next generation technologies and maintains the integrity of proprietary components.

In the near future, it is expected that OEMs will need to spend 50-60% of machine-development time focused on software requirements. This will be a big change, particularly for smaller, traditional machine builders. Only the use of standardized software and harmonized open protocols can help them handle this challenge and get machines to market in the shortest amount of time.

Scalable automation platform

Standards help enable a scalable automation platform, according to Lenze.

Cloud: An encrypted wide-area network connects to cloud-based services such as remote service, data monitoring, downtime tracking, and predictive maintenance.

Process level: A cloud interface communicates with a non-encrypted shop-floor network and machine interfaces using Profinet Ethernet communications and OPC UA.

Control level: Logic, motion controllers, and input/output (I/O) devices connect via Ethernet, programming software, and PackML and PLCopen standards.

Field level: EtherCAT Ethernet protocol connects motion controllers (drives) to I/O and third-party devices.

Actuator/sensor level: Electromechanical devices, such as motors, sensors, and other actuators, do the moving and sensing for various machines and processes, such as a case erector, a horizontal form file and seal machine, and a delta robot.

Daniel Repp is automation manager, Lenze. Edited by Mark T. Hoske, content manager, Control Engineering, CFE Media, mhoske@cfemedia.com.

KEYWORDS: Motion control standards, IIoT 

Automation standards and protocols help industrial motion control.

Interoperable network communications are critical to motion control.

Motion control OEMs and end users benefit from standards.

CONSIDER THIS

Interoperable communications among machines would make system integration and IIoT communications easier; are your vendors supporting that?