IO-Link Safety: What It Is and Isn’t

Comparing “IO-Link” and “Safety” to “IO-Link Safety”

There are many I/O blocks that have “IO-Link” and “Safety” in their descriptions, which can cause some confusion about which safety features they include. Here’s an overview of different safety-named blocks and how they compare to IO-Link Safety.

Safety Network Blocks

These blocks have I/O ports that use Pin 4 and Pin 2 as OSSD signals (safety ports). OSSD—output switching signal devices—send 24-volt signals over two wires to confirm that a device is operating in a safe condition. If 0 volts are detected in either signal, besides their safety-checking 0-volt pulses, it’s read as a safety event that signals the machine to go into a safe state. Safety network blocks are only for standard (non-network) safety devices. These blocks communicate directly back to a Safety Controller over safety protocols like CIP Safety, PROFIsafe, etc. These blocks typically can monitor between 8-16 standard safety devices. There is no intelligence built into the safety devices.

Safety Network Blocks with IO-Link

Blocks in this category usually have a mixture of I/O ports on them. The ports can range from standard I/O to standard IO-Link communication, and in addition, include ports that use Pin 4 and Pin 2 as OSSD signals (safety ports). These blocks communicate over the safety protocols with only a few ports to connect standard (non-network) safety devices. There is some versatility with these blocks since you can wire standard sensors, IO-Link devices, and safety devices to it. The drawback is, you will always run short of the port style you need and, in the end, use more blocks to cover either the safety or IO-Link needs of the application. There is no intelligence built into the safety devices.

Safety over IO-Link Blocks

In this system/architecture, there are standard IO-Link Masters communicating to the Safety PLCs/Controllers over standard protocols like EtherNet/IP, PROFINET, etc. Connected to the IO-Link Ports of these Masters are Safety over IO-Link devices, currently limited to only Safety over IO-Link hubs. The Safety PLCs/Controllers communicate via safety protocols like PROFIsafe to the standard IO-Link Master, and then using the IO-Link communication channel, they bridge the gap to the Safety over the IO-Link hub via the “black channel.” These Safety over IO-Link hub’s ports use Pin 4 and Pin 2 as OSSD signals (safety ports), so standard (non-network) safety devices can be connected. This system provided a “gap filler” while IO-Link Safety was being developed. In this system/architecture, the standard IO-Link Masters allowed standard IO-Link devices and Safety over IO-Link hubs to be connected to any ports. This brought even more versatility to an application and the beginnings of the benefits of IO-Link. Still, there is no intelligence built into the safety devices.

IO-Link Safety

IO-Link Safety adds a safety communication layer to IO-Link. The difference between this and Safety over IO-Link is that this safety layer applies to both the IO-Link Master and IO-Link Safety devices. Within a CIP Safety or PROFIsafe network, the safety communication protocol has top priority over standard EtherNet/IP or PRIFONET data if both are existing on the same physical network. The same is true for IO-Link Safety: both standard and safety IO-Link protocols can exist on the same physical cable between the IO-Link Master ports and IO-Link Safety devices, with IO-Link Safety carrying the top priority. For a deep dive into the IO-Link Safety protocol, I suggest visiting the IO-Link Consortium’s website at io-link.com. In this system/architecture, you have IO-Link Safety Masters, which communicate to the Safety PLCs/Controllers over safety protocols like CIP Safety, PROFIsafe, etc. The ports on the Masters can utilize Pin 4 and Pin 2 as OSSD signals (safety ports), so standard (non-network) safety devices can be connected. Pin 4 can also be used to carry standard IO-Link and IO-Link Safety communication to standard IO-Link devices and IO-Link Safety devices, respectively. This allows for the most versatile safety solution in the market–IO-Link Safety Masters that can accept standard (non-network) safety devices, standard IO-Link devices, and IO-Link Safety devices. Intelligence in the IO-Link Safety devices is now available.

Benefits of IO-Link Safety

    • IO-Link Safety devices are fieldbus neutral: you just need to specify the IO-Link Safety Master to match the Safety PLCs/Controllers protocol.
    • IO-Link Safety Master port versatility: standard (non-network) safety devices, standard IO-Link devices, and IO-Link Safety devices can be connected.
    • Parameter storage: standard IO-Link and IO-Link Safety device’s parameters can be stored for ease of device replacement.
    • Smart IO-Link Safety device data: more data available, like internal temperature, humidity, number of cycles, power consumption, diagnostics, etc.
    • Simplified wiring: IO-Link Safety devices are still connected to the IO-Link Master port with a standard 3 to 4 conductor cable.
    • IIoT fit: IO-Link Safety gives more visibility to upper-level systems like SCADA, allowing safety device-level monitoring.

I am looking forward to seeing how quickly IO-Link Safety will be accepted, with how IO-Link numbers have skyrocketed over the last few years. The future looks great for IO-Link with IO-Link Safety, IO-Link Wireless and in the future, Single-Pair Ethernet (SPE). With all these new capabilities, what application can’t IO-Link support?

Back to the Basics: What is the Value of IO-Link?

IO-Link

With the demands for flexible manufacturing, efficient production & visibility in our factories, smart manufacturing is driving the way we work today.  Analytics and diagnostics are becoming critical to our ability to perform predictive maintenance, improve equipment effectiveness and monitor the condition of the machine as well as the components inside the machine.  Typically, our first reaction is to put these devices onto Ethernet.  However, the implementation of Ethernet requires a high skill set that is scarce in our traditional manufacturers today.  Due to the simple control architecture of IO-Link devices, it allows for many Smart devices to provide the data we need for analytics with a reduction in the Ethernet skill set that has become a roadblock for many manufacturers.

Many people think IO-Link is a new industrial network to compete with EtherNet/IP or Profinet, but this is a common misconception. IO-Link is complementary to those networks and typically enables those networks to do even more than previously thought.

Standard IO-Link Setup_01_preview

Open Standard

IO-Link is an open standard designed with the idea to act like USB for industrial automation.  IO-Link is meant to simplify the smart sensor & intelligent device connectivity on the factory floor in a similar way that USB simplified connectivity to computers for auxiliary devices.  IO-Link is not an industrial network or fieldbus; it is an industrial network and industrial controller agnostic. Designed with a master to slave configuration, addressing of the devices is point-to-point, similar to USB.  Compatible IO-Link masters can act as slaves or nodes on a variety of industrial protocols and act complementary to the network of the user’s choosing.  Eliminating the need for serial communication configuration or network addressing simplifies the connection and integration of devices.

Value in Machine Builds

IO-Link has advantages for both machine io-link master_18x18_300dpibuilders and discrete manufacturers.  For machine builders, the biggest advantage comes from the simplified wiring scheme of IO-Link devices.  We have seen machine builder users of IO-Link reduce their wiring hardware & labor costs by 30%-60% for sensors,
outputs & controls.  This is realized with the simple sensor tool cords used for connections, quick-disconnect connectors on the cables and machine mount Ethernet masters devices.  It is also realized for machine builders in an increase of turns on their floor, a reduction in build labor and significantly faster commissioning time.

Value on the Production Floor

For discrete manufacturers, the biggest advantages have come from the parameterization and diagnostic features on the IO-Link devices.  With the ability to store & send parameters between the master & slave, IO-Link devices can be automatically configured. Hot-swapping a complex smart device like a pressure sensor can go from a stressful ordeal including 14-plus setpoints to literally a push of one button.  Combining this functionality with multiple diagnostics both in the master & slaves eliminates human error and dramatically reduces downtime & troubleshooting for manufacturers.

To learn more about market leading IO-Link technologies, visit www.balluff.com.

IO-Link Sensors in Tire Manufacturing

Much has been written here on Sensortech about IO-Link, and the advantages that an IO-Link-based architecture offers. In this article, we’ll take a look at a specific application where those IO-Link advantages are clear.

Tire manufacturing machinery in general, and tire curing presses in particular, incorporate numerous sensors and indicators that contribute to machine efficiency. As an example, tire curing presses often use magnetostrictive linear position sensors for feedback and control of mold open/close. Overwhelmingly, sensors that provide an analog, 4-20 mA signal are used. But maybe there’s a better alternative to typical analog feedback.

As discussed HERE and HERE, migration away from typical analog sensor signals to network-capable IO-Link interfaces makes a great deal of sense in many areas of application.

In a tire manufacturing operation, there are typically numerous, essentially identical curing presses, lined up in a row, all doing essentially the same job. Each press uses multiple analog position sensors that need each need to be connected to the press control system. As with pretty much analog device, the use of individual shielded cables is critical. Individual shielded cables for every sensor is a costly a time-consuming proposition. An Engineering Manager at a machine builder told us recently that wiring each press requires around 300 man hours(!), a significant portion of which is spent on sensor and indicator wiring.

Which brings us to IO-Link. Replacing those analog sensors with IO-Link sensors, allows feedback signals from multiple machines to be consolidated into single cable runs, and connected to the network, be it Ethernet/IP, EtherCat, Profinet, or Profibus. The benefits of such an approach are numerous:

  • Wiring is simple and much more economical
    • Eliminates need for shielded sensor cables
  • Integrated diagnostics allow remote machine status monitoring
  • Reduces more expensive analog IO on the controller side
  • Over-the-network configuration and the ability to store those configurations reduces setup time

And, by the way, the IO-Link story doesn’t end with position sensors. The ever-growing list of IO-Link enabled sensors and indicators allows the benefits to be rolled into many areas of machine automation, such as:

  • Intelligent IO-Link power supplies with HeartBeat technology that monitor their own “health” and report it back over the network (think Predictive Maintenance)
  • Highly-configurable IO-Link stack light alternatives that can be set up to display a number of machine and process condition states
  • IO blocks, memory modules, pressure sensors, discrete (on/off) sensors of all type, and more

To learn more about IO-Link, visit Balluff.com

1 Visual Way to Improve Operator Performace

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.

Tesla Motors Blog – Factory Upgrade

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.

Stop Industrial Network Failures With One Simple Change

Picture1

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.

2013-08-19_Balluff-IO-Link_Mexico_Manufactura-de-Autopartes_healywBy 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.

Light it Up! Industrial Stack Lights are old news…

I am seriously excited about the new Smart Light.  It will revolutionize how we automate and interface with people working in the manufacturing environment.  If you didnt watch this video… you need to watch this video.

Even if you don’t know what a stack light is, you will want one of these for your discotec to light it up!

Operating on the open communication protocol IO-Link that I have discussed in previous posts, I think this single part number will improve the factory for:

  • an operator wanting to know when to refill a feederbowl, position a part, or empty a full output bin
  • a maintenance guy needing to know what cell is causing the machine downtime
  • a plant manager wanting to know the machine output, speed, productivity

If you want more information on how this works visit the Smart Light webpage.

The Spring Line is Here!

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.

EthetNetCables_755x220To recap, remember the four short bullet points below when choosing your next cable:

  • Ethernet – transmits data
  • Ethernet/IP – transmits data to many machines/devices
  • Solid – good for long distance and little flexing
  • Stranded– good for short distance and flexing

To learn more visit www.balluff.us

2 Simple Ways to Protect from Arc Flash Hazards

If you are a manager at any level of a manufacturing facility, I hope you are aware of the dangers of arc flash.  For those who are not aware, “an arc flash, also called arc blast or arc fault is a type of electrical explosion that results from a low-impedance connection to ground or another voltage phase in an electrical system.”  Typically this does not occur in 120V situations, but can occur in 480V+ installations if proper precautions are not taken.  Employees can be severely injured or even killed when an accident occurs while working with these kinds of electrical systems.   There are many standards  like OSHA, IEEE and NFPA that regulate these types of situations to provide a safe working environment for the employee.  In addition to those standards, I would propose two simple changes to controls architecture and design to help limit the exposure to working inside an electrical cabinet.

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UHF RFID, One Size Fits All! – Really?

With the proliferation of UHF (ultra-high frequency) based RFID in the commercial and consumer markets, UHF has been seen as the mainstay now for many low-cost, long-range RFID applications. And in recent years with the desire for longer range application flexibility in the industrial sector, naturally users want to gravitate toward technologies and products with a proven track record. But can you really take the same products developed and used for the commercial and consumer logistics markets and apply them reliably to industrial applications like asset tracking, EKanban, general manufacturing or logistics?
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IO-Link is the USB for Industrial Automation

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.

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