This section introduces the various aspects of networking components to consider for an effective deployment of the VxRail system. It is important to recognize the common ports and protocols that are used in an industrial network. This helps to identify what should be seen and not seen within the network. Some of the industrial protocols inherently lack security features and can be susceptible to cyberattacks. Reduce risk by using segmentation to establish boundaries for the different protocols.

Review high-level network considerations such as scalability. Be sure to have an accurate account of the bandwidth and network size (number of devices) to confirm that enough resources have been planned to handle the current scale, and that there are no issues when the need to scale up arises. Also consider issues with convergence of the new deployment with the existing infrastructure. Consider whether any new technologies and components that are deployed will interfere with any existing ones, or perhaps how they can be consolidated. Also, think about network performance, especially as industrial networks require low latency to support the real-time requirements of many manufacturing use-cases. Lastly, review how the new components will be managed, monitored, and secured (see Cybersecurity for more detail).

An overview of commonly used industrial protocols is provided in the following sections. More details regarding their use in the DVD are provided in subsequent chapters.

OPC is the interoperability standard for the secure and reliable exchange of data in the industrial automation space and in other industries. It is platform-independent and ensures the seamless flow of information among devices from multiple vendors. The OPC Foundation is responsible for the development and maintenance of this standard. The introduction of service-oriented architectures (SOA) in manufacturing systems introduced new challenges in security and data modeling. The OPC Foundation developed the OPC Unified Architecture (OPC UA) specifications to address these issues while simultaneously providing a feature-rich technology and open-platform architecture that is future-proof, scalable, and extensible.

OPC UA goes beyond the limitations of existing OPC interfaces and provides solutions for numerous new use cases. The functionality and enhancements of OPC UA allow for implementing and using solutions on different platforms. The OPC UA standard is a platform-independent communication framework that is rapidly emerging across all types of industry.

Security is essential when exchanging information between systems. A sophisticated security-in-depth concept is built into the core of OPC UA. OPC UA defines application-level and transport-level security, built into layers on top of the TCP/IP stack. OPC UA introduces the UA-Secure-Conversation layer in addition to the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) used in HTTPS standards of modern web applications.

For standard use cases, Unified Automation developed standard products using the advantages of OPC UA. These products can be used out-of-the-box and can be combined with other systems supporting OPC UA or legacy OPC standards.

As a standard for data interoperability, the OPC Foundation facilitates the adoption of OPC technology through collaboration with other international standards organizations. These collaborative efforts provide members with new opportunities for market expansion and technology integration, as the following figure shows.

(Source: OPC Foundation: Markets and Collaboration)

MQTT is an OASIS standard messaging protocol for Internet of Things (IoT). It is an extremely lightweight protocol following publisher/subscriber messaging transport. The Dell Validated Design for Manufacturing Edge uses MQTT-based ingest from IIoT devices into SDP by publishing to an MQTT broker configured on SDP. MQTT message headers are very small and require minimal resources, making them an ideal protocol for very small devices.

EtherNet/IP is an application layer protocol that is transferred inside a TCP/IP packet, and it indicates the way in which that data is organized in a TCP or UDP packet. EtherNet/IP networks provide plant-wide network systems using open, industry-standard networking technologies. It enables real-time control and information in a discrete, continuous process for batch, safety, drive, motion, and high availability applications. The EtherNet/IP network connects devices such as motor starters and sensors to controllers and HMI devices, and on into the enterprise. It supports nonindustrial and industrial communications on common network infrastructures.

The Modbus communication protocol is the oldest and most popular automation protocol in the field of process automation and Supervisory Control and Data Acquisition (SCADA). Modbus provides a common language for devices and equipment to communicate with one another.

For example, Modbus enables measurement devices that are connected on the same network to communicate the results to a supervisory computer or programmable logic controller (PLC). The Modbus Organization is an association of users and suppliers of Modbus-compliant devices, and they manage the development and updates of Modbus protocols.

Several versions of the Modbus protocol exist for the serial port and Ethernet. The most common are:

• Modbus RTU—An open serial protocol derived from the primary/secondary architecture originally developed by Modicon (now Schneider Electric). This protocol primarily uses an RS-232 or RS-485 serial interface for communications and is supported by almost every commercial SCADA, HMI, OPC Server, and data acquisition software program in the marketplace. This makes it easy to integrate Modbus-compatible equipment into new or existing monitoring and control applications.
• Modbus ASCII—Used in serial communication. It uses ASCII characters for protocol communication. Modbus ASCII uses the ASCII character set to represent hexadecimal characters that each contain four bits of data.
• Modbus TCP/IP—Provides the transmission medium for Modbus TCP/IP messaging. Modbus TCP/IP simply combines a physical layer named Ethernet with a networking standard named TCP/IP, and a standard method of representing data that is Modbus, all of which combine to carry data of the Modbus message structure between compatible devices.
• Modbus Plus—Proprietary to Schneider Electric, and unlike the other variants, supports peer-to-peer communications between multiple primaries. It requires a dedicated co-processor to handle fast token rotation, like what is required when using High-Level Data Link Control (HDLC). It uses twisted pair at 1 Mb/s and includes transformer isolation at each node, which makes it transition/edge-triggered instead of voltage/level-triggered. Special hardware is required to connect Modbus Plus to a computer, typically a card made for the ISA, PCI, or PCMCIA bus.

Modbus is an open standard that describes the messaging communication dialog. Modbus communicates over several types of physical media such as:

• Serial RS-232
• Serial RS-485
• Serial RS-422
• Ethernet

Profibus, standardized according to EN 50170 and IEC 61158, allows communication between distributed ET 200 I/O devices, display, and operator panels, as well as other field devices with automation systems. In addition, the complete automation system can be put into operation, deployed, tested, and diagnosed using the fieldbus.

The Industrial Ethernet Standard PROFINET is the communication backbone for Industry 4.0 in automation technology. For production or process automation, PROFINET drives applications with or without functional safety or modular machine designs. It is an open architecture that converges TCP/IP (complies with IEEE 802.3) with rapid data exchange, high data speed, and deterministic communication with minimal jitter. There are several choices of media for networking (copper, glass fiber, wireless), with flexible network topologies (line, star, tree, ring), and functions to read out topologies.

PROFINET is a mechanism to exchange data between controllers and devices. Controllers could be PLCs, Distributed Control Systems (DCSs), or Programmable Automation Controllers (PACs). Devices could be I/O blocks, vision systems, RFID readers, drives, process instruments, proxies, or even other controllers.

PROFINET, the leading industrial Ethernet standard for automation, exchanges data quickly and deterministically. It creates integrated processes and configures networked interfaces. The openness and flexibility of PROFINET ensures freedom when designing a machine and system structure. Designed for efficiency, it optimizes use of available resources and significantly increases plant availability.

The DH+ protocol is an older Allen-Bradley protocol. However, it is still in use and widely recognized for simplification, making troubleshooting and repair easier. There are also many solutions for interfacing DH+ networks with other networks, due to its proven age and compatibility with other open protocols.

DH+ is designed to support remote programming on the factory floor. While the number of devices on the network are limited to 64 devices per link, there is a wide range of supported device protocols that include each of the following:

• BACnet/IP—a data communication protocol for building automation and control networks.
• ControlNet—used where the required volume of data is much higher for use in devices such as robotics, motion sensing, motion control, and visual controls. ControlNet uses the OSI model on CIP defining network protocols in seven layers. It implements CIP at the session layer and higher, but adapts CIP to ControlNet specifications at the transportation level and below. This allows it to function as a high-speed network to send time-sensitive I/O that includes configuration data and peer-to-peer data.
• DeviceNet—an open network that uses the Common Industrial Protocol (CIP) to control, configure, and collect data used in industrial devices. DeviceNet is an application-level communication protocol that is often used for industrial automation. It sits atop the Controller Area Network (CAN) and allows connections between simple, usually machine-level devices, and higher-level devices such as PLCs. DeviceNet is limited to a total of 64 nodes and is predominantly used for discrete applications within manufacturing. Depending on the end use and application, one key advantage of DeviceNet is that power and signal are provided in one cable. This gives it a cost advantage over other protocols and is highly useful in the connection of legacy equipment in IIoT deployments where connectivity is not native to the machine from the OEM.
• DNP3—based on the standards of the International Electrotechnical Commission (IEC) Technical Committee 57, Working Group 03 who have been working on an OSI 3 layer "Enhanced Performance Architecture" (EPA) protocol standard for telecontrol applications. DNP3 has been designed to be as close to compliant as possible to the standards as they existed at the time of development, with the addition of functionality not identified in Europe, but needed for current and future North American applications.