What’s New in Ethernet?


Ethernet is pretty much a defacto standard for industrial applications. Issues of transmission speed, throughput, redundancy, and topology are not the controversial subjects they once were as techniques arrived to resolve them. The latest news and trends for Ethernet center around: switches that can handle application in harsh environments, security, wireless, as well as the introduction of new Ethernet compatible versions of standard networks, some of which operate without an Ethernet switch.

N-Tron switches are encased in coated steel enclosures designed to reduce noise. They handle operating temperatures from -40 to 85¡ C, and are shock and vibration resistant. These features-plus redundant power inputs with voltage ranges of 10 to 49 Vdc make these switches well suited for use in harsh environments.

Rough and ready
N-TRON Corp., a leader in industrial networking, has a family of managed Industrial Ethernet switches. Housed in a compact, hardened, extruded aluminum enclosure the all-Gigabit 7506GX2 suits high traffic applications such as security and video surveillance. The switch features four auto-sensing 10/100/1000 Mbps Ethernet ports and two small form-factor pluggable (SFP) expansion ports for optional multimode fiber, single-mode fiber, or 1000BaseT copper connections.

“Gigabit Ethernet has the bandwidth required to support video traffic from security and surveillance cameras,” said Warren Nicholson, president and CEO, N-TRON. Security and surveillance networks can now easily tie into traditional Ethernet networks for an alternative to the proprietary systems previously used. Our N-Ring technology has the redundancy needed in critical surveillance applications, while features such as IGMP snooping and query management efficiently manage multicast video broadcasts.” IGMP snooping intelligently filters and forwards network traffic among devices automatically, with no user configuration.

N-TRON switches are rugged, durable, and industrially hardened. Encased in enclosures that reduce noise, they handle temperatures from -40 to 85¡ C, are resistant to shock and vibration, and have an MTBF of two million hours. These features-plus redundant power inputs with voltage ranges from 10 to 49 Vdc-enable them to handle harsh environments and applications in a variety of industries.

The list of functions available with these managed switches includes port trunking and port mirroring. The IGMP feature speeds deployment, eliminates configuration errors, and is useful for Opto 22 customers using distributed I/O for Allen-Bradley(r) (“IO4AB”) systems. “The N-TRON hardware's IGMP snooping function is by far the best we've seen,” says Bryce Nakatani, quality assurance engineer, Opto 22. Their managed switches deliver high throughput rates, so they suit building network architectures that use the EtherNet/IP protocol.”

The EL228, from Sixnet, is a 28 port (24 + 4G) industrial Ethernet managed switch. The 24 Fast Ethernet SFP ports can be used for any mix of copper RJ45 or fiber transceivers. The switch has LEDs, power/ground connections, console ports and bracket positions on the front and back for easier and more flexible installation.

The EL228 industrial managed Ethernet switch platform also demonstrates reliability, redundancy, and ruggedness for industrial environments. _The manufacturer, Sixnet, claims it delivers the capabilities required to enable a new generation of “smart” applications for the power and energy, transportation, and oil and gas industries. The devices withstand extreme environments, such as those found in U.S. Navy air traffic control in Antarctica and oil platforms in Oman. The switch has 24 Fast Ethernet small form-factor pluggable (SFP) ports that are field-configurable; you can match a configuration of any switch in your network.

It meets IEC 61850/IEEE1613 standards and has KEMA approval. Cyber-security features protect against unauthorized access. Fast redundancy keeps networks running even under fault conditions. Other features include real-time message delivery and multicasting.

The ability to mix and match fiber and copper ports on the fly is convenient and helps reduce costs. Plus, the EL228's multiple mounting bracket positions, movable power plugs, LEDs, and front and back console ports make it easy to stock for rapid delivery and deployment.

Security in the spotlight
The Web browser is an important window to Web-based functions of industrial Ethernet devices, including managed switches and routers. In the wake of recent high profile cyber attacks on Internet Explorer, other Web browsers are being used. Phoenix Contact reminds industrial Ethernet users that choosing Ethernet products compatible with all major Web browsers-not just Internet Explorer-is an important step in designing a secure industrial network.

Phoenix Contact offers the ILC 170 ETH 2TX controller, with two Ethernet ports that each come with a built-in Ethernet switch, eliminating the needfor a separate Ethernet switch in certain applications. The unit makes it easy to daisy-chain multiple ILC 170 controllers.

While experts warn computer users against using Internet Explorer, you may find that a number of industrial Ethernet devices will not operate with other browsers, such as Mozilla Firefox and Google Chrome.

Phoenix Contact offers EtherNet/IP Made Easy, a freeware tool for configuring managed switches and I/O for any EtherNet/IP application. It supports multiple wired or wireless adaptors and provides network discovery and IP management functions for both managed switches and I/O. Key features include the ability to monitor, set and save multicast IGMP and redundancy settings for groups of managed switches in just a few clicks. For remote I/O, EtherNet/IP Made Easy ensures quick configuration of IP67 and IP20 I/O for use with any EtherNet/IP controller.

No more wires
Opto 22 offers wireless and wired Ethernet networking options on its standard SNAP PAC programmable automation controllers (PACs) and I/O systems. “Similar to the way you use your laptop, our SNAP PAC controllers and I/O allow you to choose wired and wireless networking based on your environment and other factors,” said Nick Riley, design engineer at Opto 22. “You now have an effective way to conduct 'proof-of-concept' exploration for your projects-before investing in permanent wiring or building a wireless infrastructure throughout your factory or facility. It gives you flexible options for segmenting your network.”

SNAP PAC controllers and I/O brains, from Opto 22, let you design both wired and wireless networks. You can network components through standard wired Ethernet, use 802.11a/b/g for wireless networking, or use a combination of both. The 802.11a and 802.11g radio technologies deliver data at transmission rates of 54 Mbps.

The wireless technology is based on the industry-standard IEEE-802.11 specification with support for a, b, and g networks operating in the license-free 5 GHz (802.11a) and 2.4 GHz (802.11b/g) frequency bands. In this way the controllers and I/O brains can be used in the most common wireless infrastructures. Wireless access points, wireless routers, and wireless repeaters from nearly any vendor can co-exist with SNAP PAC wireless technology. The 5 GHz (802.11a) option lets you deploy SNAP PAC wireless in a frequency other than the typically crowded 2.4 GHz band.

Secure transmission algorithms-including WPA (TKIP) and WPA2 (802.11i/AES)-help build robust and secure wireless communications systems. In addition, SNAP PAC wireless supports either infrastructure mode, where communication among devices is routed through an access point, or ad hoc mode, where each device can detect and communicate with any other similarly configured network device within range.

Ethernet couplers
The 750-352 ECO Ethernet Fieldbus Coupler, from Wago Corp., lets you move from centralized PAC/PLCs to decentralized networks. The coupler supports MODBUS TCP/IP and EtherNet I/P, and accommodates 64 I/O modules.

Wago's Ethernet Fieldbus Coupler's compatibility with the 300+ analog, digital, and specialty modules lets you set up custom distributive control.

The DIN-rail mount, UL listed coupler ensures reliable data transmission and high-speed communication through 10/100 Mbit/s Ethernet port. The coupler's compatibility with the 300+ analog, digital, and specialty modules lets you set up custom distributive control.

The coupler can also expand the usability of connected devices, such as the Allen-Bradley(r) RSLogix(tm) 5000 systems, through downloadable add-on instructions from Wago.

The Speedway 767-2301 Ethernet Programmable Fieldbus Coupler links the IP67 Speedway 767 I/O-system to Ethernet networks. The unit's operating temperature is from -25C to +60¡C. Speedway accommodates up to 64 I/O modules/station, 8 channels/module, 512 channels/station and 50 m between digital, analog or specialty modules. All power and networking communication/signal transmission occur through M8 or M12 molded cables, which eliminate point-to-point wiring.

Redundant Ethernet technology can enhance the reliability of Ethernet installations. However, building or expanding redundant network infrastructures can be taxing due to the lack of accommodating technology. In addition, some redundant technologies are inefficient in certain situations.

A redundant industrial Ethernet network should be easy to deploy, recover quickly from failure, and be expandable. One of the more common problems is the lack of a technology that simplifies building such networks. Applications such as wind power, oil pipelines, and railway automation require large redundant Ethernet networks that may encompass multiple locations over substantial distances and require topologies that are more flexible. Turbo Chain(tm), from Moxa, can address these issues.

Existing approaches for fault-tolerance include Spanning Tree protocol (STP), Rapid Spanning Tree protocol (RSTP) and proprietary ring redundancy. STP automatically designates redundant links in an arbitrary mesh network, and then reactivates one or more of the links when an active link fails. Although this type of redundancy can be used with networks with complicated topologies, the recovery time is too slow for industrial applications.

RTSP improves somewhat on STP's slow recovery time, but remains unsuitable for many mission-critical applications. Proprietary Ring Redundancy is a cost-effective approach with good recovery times, but has limitations in topology flexibility and expandability.

The Turbo Chain(tm) system solves the slow recovery time of STP/RSTP, and the inflexible topology or restricted rings of proprietary ring redundancy. This system is used with the company's managed Ethernet switches.

It is based on the “chain” concept. You create any type of redundant topology among any network segment. Configuration involves the connection of several Ethernet switches to form a daisy chain, where a Head-Switch and a Tail-Switch (the edge switches at the two sides of the chain) are configured first, then the remaining switches are configured as member switches. Then you link the two ends of the chain to an Ethernet network.

Should a chain-segment fail, the blocked path (link between the tail-switch and the outside network) will activate instantly with a recovery time of under 20 ms.

Whenever an application calls for a multiple ring architecture, Turbo Chain(tm) offers flexible and scalable construction, unrestricted expansion, and fast fault recovery. You can create as many redundant connections as needed by simply linking a new Turbo Chain(tm) to any segment of the Ethernet Network. You do not need to reconfigure the existing network; instead, you can use Turbo Chain(tm) to scale up redundant networks directly. In addition, Turbo Chain(tm) can be connected to a network using other redundant technologies, such as STP, RSTP, and Moxa's Turbo Ring(tm).

Switchless Ethernet
Popular in Asia, CC-Link is a family of industrial networks that seamlessly fit together from the sensor/device level up to the corporate IT level. The protocol has been approved as IEC 61158 and 61784 standard for fieldbus networks. It also meets the ISO 15745-5 standard.

CC-Link IE for industrial Ethernet is a gigabit network that delivers deterministic data transmission without the need for Ethernet switches or hubs.

The latest version is CC-Link IE for industrial Ethernet. A gigabit network, it connects up to 120 stations, delivering deterministic data transmission without the need for Ethernet switches or hubs. In addition, hundreds of these networks can be interconnected for coordinated facility wide control and data integration. The protocol offers cyclic and transient (or on demand) data exchange through token-passing.

The CC-Link Field network connects PCs, PLCs, robots, servos, drives, valve manifolds, digital and analog I/O modules, temperature controllers, and other devices. It sends data at a rate of 10 Mbps deterministically.

A safety version of this protocol called CC-Link Safety complies with IEC 61508 SIL3 and EN954-1/ISO 13849-1 Category 4. This protocol will detect communication failures that may cause malfunction of the emergency stop operation. CC-Link/LT is a bit-oriented network for sensors and actuators, as well as for widespread I/O applications involving many locations of smaller increments of I/O points.

Discuss this on the Engineering Exchange:

CC-Link Partner Association


N-Tron Corp.

Opto 22

Phoenix Contact
www.phoenixcontact.com, www.phoenixcontact.com/eip



::Design World::

Speak Your Mind