Ethernet/IP, the industrial communications protocol that enables communication between machine I/O information systems, factory floor devices and enterprise systems has an open-source software stack. The stack was created and recently released by the Vienna University of Technology’s Automation and Control Institute and written in the C Programming language.

This is great from the standpoint of reducing development costs and cutting the risk of implementation. It may very well be a catalyst for vendor adoption and implementation of (the already popular) Ethernet/IP protocol. I’ll go as far as to say that it may also increase custom development from independent outfits/ system intergrators and internally within the larger industries.

Link to the license and royalty free adapter stack download @ SourceForge

Available through Sourceforge.net here, it allows users to test Industrial Ethernet TCP/IP systems that require deterministic operations. The current version analyzes network traffic and performance of a device on ODVA’s Ethernet/IP network only but NIST has said to be releasing additional versions for other Industrial Ethernet types (release date unavailable).

Test Tool for Industrial Ethernet Network Performance document (distributed by ISA)
NIST test tool download (Sourceforge.net)

So what exactly are they?

Both switch types have the capability of linking network devices together from one port to another. Unlike hubs, switches distribute data more intelligently as it interprets them and sends it out to the right destination.

Layer 2 and Layer 3 terms comes from the OSI seven Layer model (a theoretical way of dividing a network architecture up with functionality, service, dependence and application). Within the model, Layer 2 represents the “Data Link Layer” while Layer 3 represents the “Network Layer”.

Layer 2 switches have the capability of moving packets around a single network. As the reference to the OSI Layer holds true, this switch facilitates data only (and) within the physical layer (also known as Layer 1 e.g. cables and connectors). It is intelligent enough to learn the MAC addresses of each device, source/ destination of each packet and routes each packet within the single domain (at wire speed). While it breaks up a collision domain, it does not have the ability to transport the data packet from one network to another nor can it prioritize packets to guarantee bandwidth. Putting devices on a Layer 2 switch makes one entire large local segment (or what some people might call a “broadcast domain”).

Layer 3 switches act like a traditional router – it enables different network segments to be linked together. With this, data can be inter-networked from one network subnet to another. Prioritization of packets can be setup and the Layer 3 switch is intelligent enough to learn which routes are the best between the networks. While the Layer 2 switch routes packets based on MAC, Layer 3 switches route data packets based on IP. Going a step further, Layer 3 switches have the capability to logically separate networks into two or more VLANs (Virtual LANs), enhancing security and unauthorized access between networks. A Layer 3 switch typically sits above Layer 2 switches and governs the routes/ access between the different networks.

An example of this would be within a water treatment facility. Being a big treatment plant, each separate department (Clorination, Aeration, Distillation, Filtration, Waste Generation etc.) is split up into smaller/mini networks. Each mini network (consisting of PLC, I/O modules, monitors, sensors, HVAC, Historian stations and more) is controlled by its own Layer 2 switch. As all departments need the ability to synchronize, coordinate and share data with each other to perform the relevant operations, there needs to be a device that allows each data to move from one department’s network to another. That is where the Layer 3 switch comes in. All Layer 2 switches essentially converges to the Layer 3 switch facilitating inter-network data transport with the ability to prioritize packets, allow/ limit access to certain networks at any given time.

The Cisco IE-3000 switch and Transition Networks’ Milan SM801PST are examples of Layer 2 switches. The Cisco Catalyst 3750 would be a good example of a Layer 3 switch.

This is useful as a failsafe measure in the event that a link or several links are down makes it great for mission-critical applications — the technology redistributes traffic across the remaining active links with total transparency and speed. Distribution of loads across ports is based on Cisco’s proprietary algorithm which is calculated on the source/ destination IP, MAC and TCP/UDP port numbers.

EtherChannel is normally used within a network backbone rather than direct connections with end user devices/ machines. Connecting up end user devices would require the NIC / adapter of that particular device to be EtherChannel compatible. As of today, I don’t believe there is any PLC or embedded end user manufacturing/ control system device supporting EtherChannel, but that may change if the demand arises.

The maximum active number of ports that you can use with EtherChannel is eight (min. is two), regardless of the type of cable or whether it is Fast Ethernet, Gigabit Ethernet or 10 Gigabit Ethernet; with another one to eight ports acting as failover ports. The bandwidth is directly proportional to the ports and speed you use e.g.  5 ports running EtherChannel would give you 500 Mbit/s, 5 Gbit/s or 5 Gbit/s at Fast Ethernet, Gigabit Ethernet and 10 Gigabit Ethernet speeds respectively. This makes it very scalable as your traffic grows — a huge benefit.

When using EtherChannel, three things must apply:

1) All ports must be set to the same speed throughout

2) All links must comply with the IEEE 802.3 standard

3) All connected devices must support EtherChannel as well

One may argue the fact of why you would want to use EtherChannel when STP (Spanning Tree Protocol) is available. The answer would be that STP essentially limits the multiuse of links between switches and sends packets down one path at a time i.e. STP shuts down the extra redundant links. The use of EtherChannel allows the use of all available links between two devices at all times. You can use STP with EtherChannel to have a loop free topology and to prevent flooding of a network.

With all the good things being said, there is a drawback … EtherChannel is only limited to devices that support the proprietary technology. Therefore, you are bound by certain device manufacturers (mainly Cisco and Intel*). IEEE does have a similar open standard equivalent called IEEE 802.3AX (formerly IEEE 802.3ad).

*Intel has the capability to implement either the EtherChannel or IEEE 802AX within their Intel® PRO/100, PRO/1000, PRO/10GbE, Gigabit, and 10 Gigabit server adapters.

Inter-networking aside, I like how it shows the data packets are padded, striped and formed back together again, and how the network components are broken down — a rudimentary way of what happens behind the scenes in a tradition Ethernet network. This is a must see for everyone trying to grasp the concept of Ethernet networking.

Part 1

Part 2

“Cisco makes switches for Industrial Ethernet applications?” and “Cisco makes industrial switches?”, are what I hear commonly.

Yes, Cisco does make industrial switches (and I don’t mean the *old* Cisco Catalyst 2955). I am talking about the modular based IE3000 series switches. In fact, the press release for it was about a year ago (with a 2nd quarter ‘08 release). With the abundance of Industrial Ethernet switch products already in place, Cisco may have come into a crowded marketplace with some catching up to do with the established *players*.

When I think of Cisco nowadays, I think of Cisco’s Unified Communications — which includes IP telephony, unified messaging, customer contact, Web and video conferencing etc. That’s kind of edged in my mind as with the great simplistic (yet powerful) marketing they’ve done.

Cisco in industrial automation and the factory floor? Not so much. I can’t remember the time I have actually seen a Cisco IE3000 printed ad, or is there even one? They don’t even have a direct link in their main Cisco website. One will have trouble ever finding it (being buried several levels down); good thing I have got it bookmarked. For your reference, here is the direct link to their Ethernet to Factory floor solution.

Are they taking a step back because of their partnership with Rockwell Automation, letting Rockwell be the front player in marketing the Cisco switch range? Rockwell branded Cisco switches differ from the standard IE3000 models as they have inbuilt feature sets and reference architectures tailored to Rockwell’s Integrated Architecture™ applications. Cisco also has a partnership with Honeywell as well (that one we hear even less off).

The IE3000 series targets industrial automation (with the familiar PLC DIN-rail mounted form factor design and the bells & whistles of extended environmental rating, convection cooling, alarm relays, surge/ noice immunity, 24VDC power etc.), outdoor video and transportation systems control, substation automation specifications (incl. IEC61850 and IEEE1613), railway, military and other unique environmental situations. It comes in 4 ports and 8 port versions with expansions modules and SFP transceivers.

Here is a video of the IE3000 as demonstrated by their product manager.

How they will fair remains to be seen … this is relatively an early stage of them entering the already abundant industrial switch marketplace. However, with their track record, I’ll never count them out. I liken them to the Goliath of the network world with a silent but deadly presence.

Cisco IE3000 brochure

Cisco IE3000 data sheet

Shop Cisco IE3000

The Industrial Cabling Sub-committee received approval to publish ANSI/TIA 1005, Telecommunications Infrastructure Standard for Industrial Premises, at the October TIA TR-42 TR-42.9 meeting held in Vancouver, BC. TIA-1005 was created to address new structured cabling concepts for industrial installations. Specifically, it addresses the potential exposure of cable to hostile environments, and special cabling system requirements. (Source: Superior Essex)

The standard would be a huge step towards gaining further traction for the use of Ethernet in factory production and manufacturing environments. It will address several areas like the installation and requirements of cables within harsh environments, helping enable the installation of telecommunications infrastructure on the plant floor and between manufacturing/ industrial buildings.

TIA-1005 will introduce a 2 pair cabling installation allowance, a huge difference from the current TIA-568-B 8 pair standard. Also expect the inclusion of cabling concepts for automating outlets, Cat 6 allowance in automation islands; and the definition of the factory floor, work area and automating island using the MICE model/ table.

Using the MICE model, there will be a designation of four environmental areas of which the cable will be subjected to:

The industrial areas and mixed environments are then classified based on the limits of MICE to form the following levels: Mice 1 (commercial/ office environments), Mice 2 (Light industrial/ work areas), and Mice 3 (the automation island/ heavy industrial). The work area would typically be where the control level hardware resides and the automation island would be where the plant floor machines reside. Automation islands are where the harshest environments reside. Duly note that these classifications are concepts and not mandatory requirements.

The TIA-1005 is based on existing cabling standards of ANSI/TIA/EIA 568-B, 606-A; TIA-5690B; ANSI-J-STD-607-A and ISO/IEC11801.