Connecting to the Cloud: ODVA's Efforts to Facilitate Cloud Communications with EtherNet/IP & DeviceNet

Connecting to the Cloud: ODVA's Efforts to Facilitate Cloud Communications with EtherNet/IP & DeviceNet

By Bill Lydon, Editor, Automation.com

Connectivity is the name of the game in today’s IIoT atmosphere and ODVA is the latest to join the push for open communication standards. ODVA’s Common Industrial Cloud Interface (CICI) Special Interest Group is working on enhancements to ODVA specifications to connect CIP (Common Industrial Protocol) protocols, EtherNet/IP & DeviceNet with cloud applications.  Stephen Briant, a Technology Manager at Rockwell Automation  as well as the Common Industrial Cloud Interface (CICI) SIG Chair presented this information along with Thomas Whitehill, a Remote Services Architect for Schneider Electric at the 18th annual ODVA industry conference & annual meeting from February 21-23, 2017.  

This Special Interest Group (SIGs) is a formal technical working group that has been approved to develop enhancements to the ODVA Specifications, as well as guidelines and recommendations for the application of ODVA technologies.   The goal of the CICI SIG, as explained by Stephen Briant, is to develop standards that enable new cloud applications to be developed by the ODVA community, by leveraging data available in devices that conform to ODVA standards.  The plan is to accomplish this by using today’s available “cloud technologies” and “connect” them with the information defined in CIP Devices in a simple and secure manner. The SIG will focus on establishing the means for cloud applications to be able to discover CIP devices and utilize the data available in those devices. The SIG will also look for opportunities to manage devices and collections of devices through gateways.

The Scope of ODVA’s Effort 

ODVA’s scope of work for developing the Common Industrial Cloud Interface encompasses two elements in the industrial cloud ecosystem: a cloud gateway appliance (Gateway) and an application program interface (API) for the transport of bidirectional data from an on premise Gateway to cloud applications.  The ODVA vision for this Common Industrial Cloud Interface, along with the CIP industrial protocols, is to accelerate an architectural transformation by leveraging cloud computing to support device management, process analytics, notifications, remote access, virtualization, visualization and, in the future, control.

Open Communications Light the Path

In the presentation, Thomas Whitehill noted that there are several open communication protocols, being discussed as possible solutions, that are already in use today for cloud applications. These include:

AMQP - Advanced Message Queuing Protocol is the open standard and has emerged as a very popular protocol for sending messages to and receiving messages from Cloud-based systems.  Microsoft Azure IoT Hub directly supports AMQP. 

MQTT - Message Queue Telemetry Transport is an ISO standard (ISO/IEC PRF 200922), publish/subscribe, lightweight messaging protocol used for Cloud-connectivity for limited network bandwidth, remote applications.  Amazon Web services for Internet of Things (AWS IoT ) directly supports MQTT. 

JSON - JavaScript Object Notation is a terse, readable, structured data format. It is very popular as a payload format for Device-to-Cloud and Cloud-to-Device messaging. A benefit to using JSON is that many stream processing applications are built to natively consume JSON structures efficiently and cost-effectively.

Editor’s Note: This comparison is a bit like apples and oranges, since JSON it is not a transport protocol.

ODVA’s Small Packet Focus

So why is ODVA advocating Internet oriented formats. such as JSON (JavaScript Object Notation) for sending data. As opposed to the OPC UA industrial standard? As Tom Whitehill vigorously explained, the interface of CIP data to the cloud needs to be in a highly compact format in order to economize communications costs and yet still provide a format with which cloud developers are comfortable.  Whitehill emphasized that, in his experience, messages communicating with cloud applications must be “infinitesimally small” because of the high costs of that communication.  “Even though processing of a message might be infinitesimally small, in the world of cloud and big data we are dealing with an infinite numbers of messages coming in,” explained Whitehill,”Infinitesimally small multiplied by infinity is a really big number and that number can reduce your profit margin.” 

Simplifying the Gateway

ODVA’s SIG seeks to optimize the transport of data between the cloud and ODVA CONFORMANT devices that support EtherNet/IP and DeviceNet. By so doing, the SIG intends to enhance the value of EtherNet/IP by optimizing high performance, secure communications -- between Devices, a CIP-enabled Industrial Control System (ICS) and the Cloud -- as well as to simplify common tasks that must be performed by the Cloud Gateway Appliance (Gateway).

The CICI SIG work will result in The Common Industrial Cloud Interface Spécification, a major new addition to ODVA’s technology portfolio.

The Three Guiding Principles of ODVA’s CICI SIG

In his presentation, Briant shared the three guiding principles for the CICI:

Security

All communication must be initiated from the device or gateway.

Performance

Communication must be performant and scalable across the Reference Architecture, therefore CIP must “stay home” or stay on premise

Four V’s of Big Data

  • Volume (must handle the scale of data)
  • Variety (must handle different forms of data)
  • Velocity (must handle the speed required for analysis of the data)
  • Veracity (must handle the uncertainty or quality of the data)

The Components of ODVA’s Reference Architecture

The three main architectural components in this reference architecture are the CIP Device, the CICI Gateway, and cloud services.

CIP Device

In the context of CICI reference architecture, a Device is a CIP-enabled mechanism connected to a CIP-enabled network. The CIP Device’s purpose doesn’t change within the CICI context, nor do its characteristics or behaviors.

In the CICI Reference Architecture, a CIP Device engages in an extended architectural context that includes the Cloud. In this wider context, a CIP Device’s data (telemetry, etc.) can be published (indirectly) to the Cloud - to be processed, stored and analyzed by services and applications executing there. Likewise, commands and notifications can originate from those same cloud-based applications and be pushed back down through the CICI Reference Architecture to CIP Devices. The deployment of CICI Gateways is what makes this possible.  No CIP Device changes are required for it to interoperate within the CICI Reference Architecture.  CIP Devices in the CICI reference architecture are decoupled from the Cloud by the CICI Gateway, with all integration requirements handled by the Gateway.

CICI Gateway

A CICI Gateway is an on-premise physical device that bridges the gap between the CIP network and the Internet/Cloud.  This Gateway maintains contextual information for CIP Devices and contains context (e.g. security credentials, endpoint URIs, etc) for multiple Cloud-based services and messaging systems.  A CICI Gateway performs a number of roles, including bi-directional secure routing of Device-to-Cloud (D2C) and Cloud-to-Device (C2D) messages between CIP Devices on its downstream interface, and Cloud-based services and applications on its upstream interface.

A CICI Gateway translates and normalizes message payloads as they pass across the domain boundaries of CIP and the Cloud.

Deriving actionable value-impacted data, of primary importance to many customers, is the ultimate goal of CICI. For example, high levels of cost reduction can be achieved in the area of asset maintenance. As device monitoring is increasingly understood and analyzed, maintenance action can evolve from costly run-to-failure (reactive), to more efficient preventive (proactive), to the most cost effective, predictive.

Use Cases for Initial Applications

Briant and Whitehill also discussed several device lifecycle use cases which show the most obvious initial applications.

Commissioning

  • Out-of-the-box definitions (Inquiry, Command)
  • Cloud Registration / backend business setup (Inquiry, Command)
  • On-boarding/Provisioning (Inquiry, Command)
  • Context of device in application (Inquiry, Command)
  • Control/Application loading (Inquiry, Notification, Command)

Operating

  • Monitoring (Telemetry)
  • Maintenance (Telemetry, Command)
  • Calibration (Inquiry, Command)
  • Diagnosis (Telemetry)
  • Enable/Disable (Command)
  • Optimization / Changing Parameters / Programs (Telemetry, Command)
  • Software updates (Inquiry, Notification, Command)
  • Device Replacement (Inquiry, Command)

Decommissioning

  • Removing a device (Telemetry, Command)

The Open SIG Invitation

Concluding his presentation, Briant invited interested parties to consider joining the Common Industrial Cloud Interface SIG. Those interested should contact ODVA via email

Bill’s Thoughts & Observations

Considering the ODVA CICI and other initiatives, it is becoming increasingly clear that communication and integration with the cloud is huge focus for the industrial automation industry. It is likely that this focus on communication and connectivity will see a proliferation of competing protocols, methods, frameworks, and data formats, throughout the automation industry. All this means is that automation professionals are due for even more exciting, albeit confusing, times. Stay tuned to Automation.com as we cover all the latest news and releases from around the industry

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Resources

ODVA White Paper: Common Industrial Cloud Interface – Uses Cases and Technical Requirements for Data Transfer

ODVA Common Industrial Cloud Interface – Uses Cases and Technical Requirements for Data Transfer Conference Presentation 

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