EtherNet/IP
Key technology trends
EtherNet/IP utilizes ODVA’s CIP application layer and deploys it on standard networking technology such as Ethernet, Wi-Fi, or 5G. CIP is an object-oriented approach to designing Industrial IoT devices, which shortens the learning curve for developers. EtherNet/IP also defines a suite of CIP services for delivering real-time, safe, secure and application specific functions that industrial automation practitioners require with CIP Safety, CIP Sync, CIP Motion, CIP Energy, and CIP Security. “Encapsulation of CIP along with TCP and UDP into an IP packet is used to route messages vertically through an organization’s enterprise to allow the data to be consumed by business systems such as manufacturing execution systems, enterprise resource planning software, and even to cloud-based applications. Using TCP, UDP, and IP ensures that EtherNet/IP is IT friendly. Furthermore, the same class of switches and routers used in established Enterprise networks can also carry EtherNet/IP OT traffic,” he added. CIP Security on EtherNet/IP allows users to extend a defense-in-depth approach to the EtherNet/IP network to help protect EtherNet/IP IIoT devices from cyberattacks. Additionally, CIP Security enables policy-based application authentication and authorization for EtherNet/IP IIoT devices. EtherNet/IP supports a range of topology options and functionality that allow end users and OEMs to tailor the EtherNet/IP network to their needs. For example, device level ring (DLR) with specially enabled EtherNet/ IP IIoT devices provides an option for singlering network resiliency. QuickConnect™ functionality is also an option to rapidly exchange different discrete IIoT devices. Since EtherNet/IP is compliant with IEEE Ethernet standards, users can take advantage of speeds of up to 1 Gigabits per second (Gbps) and more as needed. Media installation options include copper, fiber, fiber ring, and high speed and bandwidth wireless solutions such as Wi-Fi and 5G. Reliance on IEEE and IEC standards also means that users can take advantage of new advancements in Ethernet technology. This includes Single Pair Ethernet reaching resource-constrained devices in cabinets and using the EthernetAdvanced Physical Layer for accessing devices in the field for process automation hazardous applications.
Impact of SPE and Ethernet-APL
Beydoun said that it's important to note that Single Pair Ethernet (SPE) encompasses 10BASE-T1L General Purpose SPE applications, 10BASE-T1S in-cabinet applications, and 10BASE-T1L Ethernet-APL applications. Furthermore, there are multiple IEEE SPE standards in addition to those discussed here. The functionality in EtherNet/IP for
38
in-cabinet resource-constrained device connectivity powered by SPE (10BASE-T1S) allows for the usage of a flat cable to reduce material cost, space used, and installation time. The flat cable includes both switched power, network power, SPE, and a select line to enable multi device connectivity at a low cost. This compact low-cost flat cable allows devices to be easily attached via a safe and simple piercing connection. Ethernet-APL (10BASE-T1L) supports trunk and spur, line, and star topologies as well as Type A fieldbus cable to meet the requirements of the process industries. The trunk and spur topology will be seen in the vast majority of instances for powered and intrinsic safety applications, but a ring topology is possible for non-powered and non-IS applications to enable redundancy for critical applications in sectors such as Water Treatment Plants. Ethernet-APL also enables the use of Parallel Redundancy Protocol (PRP) for network technology that have this as an option, as EtherNet/IP does. EtherNet/IP will be able to expand precise, efficient Ethernet-based control and commissioning across process field instrumentation via the Ethernet-APL physical layer. The full use of EtherNet/IP in process automation will enable concurrent seamless connectivity from the field devices to the controllers, to Industrial IoT applications, as well as the edge and cloud for prognostic analysis.
EtherNet/IP targeted applications
“Wireless and wireless safety are some of the newest applications where EtherNet/IP is being leveraged as a solution. Motion control and other applications requiring high speed reaction times are still typically best served by wired solutions,” Beydoun said. “However, for time-critical safety and I/O applications, wireless is increasingly becoming an option. An Automated Guided Vehicle (AGV) in a factory that is moving on a fixed route to supply components to a machine or to transport finished goods from a packaging line to a delivery vehicle loading area in an environment with people working on other tasks is an example where EtherNet/IP and CIP Safety can be used.” The individual devices can use the CIP Safety protocol to detect failures in communications and bring the system to a safe state. This is made possible through the “gray channel principle”, which is laid out in IEC 61508. The concept is that two safety devices must have enough intelligence in themselves, and enough diagnostics in their communications, that the entire communication network has zero impact on the ability of the device to detect communication errors. Wireless AGVs can transmit data about the number of components or finished goods that
have been transported over a given period of time to provide a better understanding of operations and how to improve them. This data can be transported either to the edge or to the cloud for further processing or inclusion in KPI dashboards making the promise of IIoT a reality. Furthermore, a degradation in AGV functionality measured via decreased speed and/or increased vibration could be used to predict future failure thereby allowing for preventative maintenance efforts to maintain maximum OEE.
Engineering challenges
EtherNet/IP already has and will continue to undergo enhancements to meet engineering challenges such as connectivity beyond wires, simpler and less expensive SPE cabling for process and discrete applications, increased speed, and enhanced coexistence on the wire. The challenge of network convergence is particularly noteworthy given both the scope of the task as well as the expected benefits of manufacturing optimization and flexibility. EtherNet/IP plans to support the currently in process IEC/IEEE 60802 Time Sensitive Networking (TSN) standard upon completion, which is expected to improve coexistence in an effort to offer end users better visibility into operations and to more easily implement their systems. “EtherNet/IP is already strongly positioned to meet the needs of time sensitive applications, flexibility in network design, and Industry 4.0/IIoT with implementation of proper network segmentation. EtherNet/ IP is designed to both move I/O traffic deterministically and quickly via low overhead UDP while at the same time allowing for more complex messaging to higher network levels including ERP systems and the cloud with TCP,” Beydoun said. Through the use of a planned gateway device, EtherNet/IP will have a unique advantage with the addition of 60802 TSN by being able to both fully adhere to the mechanisms outlined in the IEC/IEEE 60802 TSN profile as well as the IEEE 1588 Precision Time Profile through CIP Sync and CIP Motion. CIP Sync is an existing network mechanism for applications where tight real-time synchronization is vital between distributed intelligent devices and systems. CIP Motion is a current deterministic network solution for multi-axis, distributed motion control. 60802 based TSN will serve as an additional layer of control and interoperability that EtherNet/IP users can utilize to enable network convergence with other types of Ethernet traffic, such as coexistence with cameras for high-speed scanning or security, while having all applications respect the same Quality of Service considerations. Al Presher, Editor, Industrial Ethernet Book.
in d u s t r ial et h er ne t b o o k
08.2022
