An industrial Ethernet network is vastly different from an office Ethernet network in several key ways, and the key to optimizing your industrial network in light of these differences, is hands-on training.
First of all, the environment in industrial applications can degrade the actual cable itself. Some cable manufacturers actually rate their cables’ ability to withstand these environmental factors. They use the acronym MICE, and rate the cable as appropriate for one of three environments: M1I1C1E1 for office environments, M2I2C2E2 for light industrial environments, and M3I3C3E3 for industrial environments. The letters actually stand for: Mechanical factors such as shock and vibration, Ingress from moisture, Climatic factors such as temperature and sunlight, and Electromagnetic interference such as noise caused by inductive loads, welders, variable frequency drives, etc. Other cable vendors observe the recommendations of ODVA and offer cables that are ODVA compliant.
Secondly, industrial Ethernet networks can have a high amount of multicast traffic. In the early years of Ethernet hubs were used to link devices. The problem is that information coming into one port of a hub was redirected to all of the other ports on the hub. With the advent of switches, unicast traffic was now directed to only the port for the intended recipient device. This is true for both managed and unmanaged switches: they both handle unicast traffic well. The problem for the unmanaged switch comes when you encounter multicast traffic. Since an unmanaged switch does not employ IGMP Snooping (Internet Group Management Protocol), the switch does not know what to do with multicast traffic. It starts acting like the old hubs: it directs all multicast traffic to all ports. With a managed switch and with IGMP Snooping turned on, the switch knows exactly where to send this multicast traffic and directs it only to the intended recipients. Multicast traffic can be anything from produced tags to input modules configured for multicast. These can be very common in industrial applications using PLCs.
Thirdly, we now have tools available in many switches and routers to prioritize the traffic on an Ethernet network. This becomes especially important when you have high-speed applications, motion applications, or time synchronization applications. In the past all Ethernet data was equal. The feedback coming from a servo drive had to wait just as long as a person trying to get online with a PLC. Now many automation vendors are marking their data with priority codes. Allen-Bradley marks their data in layer three with DSCP markings, and Siemens uses layer two markings with PCP marks, for instance (a VLAN tagging mechanism). In either case, if your switch or your routers are not configured properly to recognize and use these priority codes, you are not taking advantage of the QoS feature that could help get your important data through first (Quality of Service).
Only through proper training can you learn not only what the key issues are but also how to properly deploy your hardware to fully optimize your network. Balluff offers hands-on training with actual automation equipment, switches, and routers to help you do just that. You can learn more about the courses Balluff has to offer at www.balluff.us.
Many manufacturers I talk to are excited about the possibilities that our new Smart Light technology, used in level mode, brings to their production or machines. Here’s a video if you havent seen it yet:
It works over virtually any industrial network with an open standard called IO-Link, which I’ve discussed many times in previous posts.
What I’m really impressed with is the number of people integrating the level mode as a quick and easy way to give instantaneous feedback to an operator on their performance to a quota or as a count-down timer. Here you can see in the middle of the right photo a bright green bar light just to the left of the red kanban rack. There are multiple of these lights in this image.
This light is a five zone Smart Light operating in level mode. As the cycle time winds down, the light decreases in value until there is no more time, at that point it flashes bright red to notify the operator to cycle to the next vehicle. It keeps the production on track and helps operators know quickly and easily how much time remains. What I’ve been told is nice about this is how bright the light is and that it is easily install-able without a controls cabinet or slice i/o j-box like you can see in the photo. Others like it because it makes the data visual from all over, where HMIs require you to stand right in front of them for information.
So if you are trying to think about ways to visualize data in your process or production to operators or managers, there are many others out there already using Smart Light for that application. Check it out.
It’s the worst when a network goes down on a piece of equipment. No diagnostics are available to help troubleshooting and all communication is dead. The only way to find the problem is to physically and visually inspect the hardware on the network until you can find the culprit. Many manufacturers have told me over the past few months about experiences they’ve had with down networks and how a simple cable or connector is to blame for hours of downtime.
By utilizing IO-Link, which has been discussed in these earlier blogs, and by changing the physical routing of the network hardware, you can now eliminate the loss of communication. The expandable architecture of IO-Link allows the master to communicate over the industrial network and be mounted in a “worry-free” zone away from any hostile environments. Then the IO-Link device is mounted in the hostile environment like a weld cell and it is exposed to the slag debris and damage. If the IO-Link device fails due to damage, the network remains connected and the IO-Link master reports detailed diagnostics on the failure and which device to replace. This can dramatically reduce the amount of time production is down. In addition the IO-Link device utilizes a simple sensor cable for communication and can use protection devices designed for these types of cables. The best part of this is that the network keeps communicating the whole time.
If you are interested in learning more about the benefits that IO-Link can provide to manufacturers visit www.balluff.us.
In today’s industrial market, Ethernet cable is in high demand. With words like Ethernet, Ethernet/IP, solid, and stranded, making a decision from the different types of cable can be difficult.
I want to make it easy for you to pick the right cable to go with the network of your choosing. As a network, Ethernet is easy to install and it is easy to connect to other networks – you can probably even have Ethernet network devices connect to your current network.
So, let’s start with the basics…First, what is the difference between Ethernet and Ethernet/IP? They both have teal jackets (hence the title – The “Spring Line”) due to the industrial Ethernet standards in North America. So, the difference between the two is in the application. Ethernet is a good networking cable that transmits data like an internet cable. Ethernet/IP transmits data and also has an industrial protocol application. The Industrial Protocol (IP) allows you to transmit more data if you have a lot devices connected to each other or a lot of machines moving at once. Ethernet/IP resists against UV rays, vibrations, heat, dust, oil, chemical, and other environmental conditions.
Next, there are two kinds of Ethernet IP cables: Solid and Stranded. Solid is great for new applications that require high-speed Ethernet. The solid cables can transmit and receive across long distances and have a higher data rate compared to stranded. The downside is that solid cables can break, and do not bend or flex well. Stranded is a better cable if you have to bend, twist, or flex the cable. It’s also better if you have to run short distances. Stranded is made up of smaller gauge wires stranded together which allows the cable to be flexible and helps protect the cable. They move with the machine and will not break as easily as solid cables.
To recap, remember the four short bullet points below when choosing your next cable:
Ethernet – transmits data
Ethernet/IP – transmits data to many machines/devices
I’ve recently heard this comparison used a number of times and the parallels are quite interesting. USB was designed to help standardize a dizzying array of connectors and configurations of supplementary devices that developed during the age of the Compaq vs IBM. It always took days to configure and establish communication between devices and then finally you could never get all the functionality that the device promised because of your PC’s specific configuration. USB revolutionized the personal computer by allowing for a standard interface for simple devices from hard-drives to keyboard lights, and best of all by offering a device drivers the functionality promised could be delivered. If the device broke, you bought a new one, plugged it in and it worked.
Everyone likes things on demand right? Movies, TV shows, chocolate, you name it. My good friend, John Harmon, has prepared a YouTube video so that you have at your fingertips an on-demand presentation on Distributed Modular I/O. It is a great overview of the available functionality of Distributed Modular I/O and what kinds of control products that are available utilizing this technology. I realize the video is seven and a half minutes, which is pretty long for a web video, but I think he does an excellent job of keeping your attention and demonstrating the value of this technology. Grab a soda and your favorite chocolate bar, put your phone on silent, and hit play on this excellent presentation.
In April, Jim Montague of Control Design wrote an interesting article on Machine Mount I/O entitled “Machine-Mount I/O Go Everywhere.” I think the article makes some very good points as to the value of why someone wants to move from inside an enclosure, or controls cabinet, to mounting I/O products directly on the machine.
He summarizes, with the help of a number of industry experts, the below points:
I recently had the opportunity to attend Hannover Fair in Germany and was blown away by the experience… buildings upon buildings of automation companies doing amazing things and helping us build our products faster, smarter and cheaper. One shining topic for me at the fair was the continued growth of new products being developed with IO-Link communications in them.
All in all, the growth of IO-Link products is being driven by the need of customers to know more about their facility, their process and their production. IO-Link devices are intelligent and utilize a master device to communicate their specific information over an industrial network back to the controller. To learn more about IO-Link, read my previous entry, 5 Things You Need to Know about IO-Link.
Valve manifolds, or islands or banks, are used by many automation engineers in their machine design. They are a great way to easily implement a large number of pneumatic motion applications while keeping the air infrastructure minimal. Recent demand in the market has driven manifold manufacturers to reluctantly embed network interfaces and remote I/O into their products. Customers tell me while manufacturer’s expertise may lie with the pneumatic side of the product; there is usually less knowledge with-in their organizations to work on the Ethernet side of the product.
EUROMAP is an association of plastics and rubber machinery manufacturers based in Austria, France, Germany, Italy, Luxembourg, the Netherlands, Spain, Switzerland, Turkey and the United Kingdom. This group has produced a comprehensive set of Technical Recommendations for its members to follow.
The EUROMAP technical committee has recommended implementation of realtime Ethernet communications for peripheral devices. Document 75-2, for example, defines network architecture and specifications for line topology (daisy chain), ring topology, and star topology.
If you are thinking about network topology and communication protocols for your project, the EUROMAP Technical Recommendations can provide valuable examples of best practices as determined by a group of leading-edge industrial machinery companies.