Posted on

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?

Posted on

How TSN boosts efficiency by setting priorities for network bandwidth

As manufacturers move toward Industry 4.0 and the Industrial Internet of Things (IIoT), common communication platforms are needed to achieve the next level of efficiency boost. Using common communication platforms, like Time-Sensitive Networking (TSN), significantly reduces the burden of separate networks for IT and OT without compromising the separate requirements from both areas of the plant/enterprise.

TSN is the mother of all network protocols. It makes it possible to share the network bandwidth wisely by allocating rules of time sensitivity. For example, industrial motion control related communication, safety communication, general automation control communication (I/O), IT software communications, video surveillance communication, or Industrial vision system communication would need to be configured based on their time sensitivity priority so that the network of switches and communication gateways can effectively manage all the traffic without compromising service offerings.

If you are unfamiliar with TSN, you aren’t alone. Manufacturers are currently in the early adopter phase. User groups of all major industrial networking protocols such as ODVA (CIP and EtherNet/IP), PNO (for PROFINET and PROFISAFE), and CLPA (for CC-Link IE) are working toward incorporating TSN abilities in their respective network protocols. CC-Link IE Field has already released some of the products related to CC-Link IE Field TSN.

With TSN implementation, the current set of industrial protocols do not go away. If a machine uses today’s industrial protocols, it can continue to use that. TSN implementation has some gateway modules that would allow communicating the standard protocols while adding TSN to the facility.

While it would be optimal to have one universal protocol of communication across the plant floor, that is an unlikely scenario. Instead, we will continue to see TSN flavors of different protocols as each protocol has its own benefits of things it does the best. TSN allows for this co-existence of protocols on the same network.

 

Posted on

The Emergence of Device-level Safety Communications in Manufacturing

Manufacturing is rapidly changing, driven by trends such as low volume/high mix, shorter lifecycles, changing labor dynamics and other global factors. One way industry is responding to these trends is by changing the way humans and machines safely work together, enabled by updated standards and new technologies including safety communications.

In the past, safety systems utilized hard-wired connections, often resulting in long cable runs, large wire bundles, difficult troubleshooting and inflexible designs. The more recent shift to safety networks addresses these issues and allows fast, secure and reliable communications between the various components in a safety control system. Another benefit of these communications systems is that they are key elements in implementing the Industrial Internet of Things (IIoT) and Industry 4.0 solutions.

Within a typical factory, there are three or more communications levels, including an Enterprise level (Ethernet), a Control level (Ethernet based industrial protocol) and a Device/sensor level (various technologies). The popularity of control and device level industrial communications for standard control systems has led to strong demand for similar safety communications solutions.

Safety architectures based on the most popular control level protocols are now common and often reside on the same physical media, thereby simplifying wiring and control schemes. The table, below, includes a list of the most common safety control level protocols with their Ethernet-based industrial “parent” protocols and the governing organizations:

Ethernet Based Safety Protocol Ethernet Based Control Protocol Governing Organization
CIP Safety Ethernet IP Open DeviceNet Vendor Association (ODVA)
PROFISafe PROFINET PROFIBUS and PROFINET International (PI)
Fail Safe over EtherCAT (FSoE) EtherCAT EtherCAT Technology Group
CC-Link IE Safety CC-Link IE CC-Link Partner Association
openSAFETY Ethernet POWERLINK Ethernet POWERLINK Standardization Group (EPSG)

 

These Ethernet-based safety protocols are high speed, can carry fairly large amounts of information and are excellent for exchanging data between higher level devices such as safety PLCs, drives, CNCs, HMIs, motion controllers, remote safety I/O and advanced safety devices. Ethernet is familiar to most customers, and these protocols are open and supported by many vendors and device suppliers – customers can create systems utilizing products from multiple suppliers. One drawback, however, is that devices compatible with one protocol are not compatible with other protocols, requiring vendors to offer multiple communication connection options for their devices. Other drawbacks include the high cost to connect, the need to use one IP address per connected device and strong influence by a single supplier over some protocols.

Device level safety protocols are fairly new and less common, and realize many of the same benefits as the Ethernet-based safety protocols while addressing some of the drawbacks. As with Ethernet protocols, a wide variety of safety devices can be connected (often from a range of suppliers), wiring and troubleshooting are simplified, and more data can be gathered than with hard wiring. The disadvantages are that they are usually slower, carry much less data and cover shorter distances than Ethernet protocols. On the other hand, device connections are physically smaller, much less expensive and do not use up IP addresses, allowing the integration into small, low cost devices including E-stops, safety switches, inductive safety sensors and simple safety light curtains.

Device level Safety Protocol Device level Standard Protocol Open or Proprietary Governing Organization
Safety Over IO-Link/IO-Link Safety* IO-Link Semi-open/Open Balluff/IO-Link Consortium
AS-Interface Safety at Work (ASISafe) AS-Interface (AS-I) Open AS-International
Flexi Loop Proprietary Sick GmbH
GuardLink Proprietary Rockwell Automation

* Safety Over IO-Link is the first implementation of safety and IO-Link. The specification for IO-Link Safety was released recently and devices are not yet available.

The awareness of, and the need for, device level safety communications will increase with the desire to more tightly integrate safety and standard sensors into control systems. This will be driven by the need to:

  • Reduce and simplify wiring
  • Add flexibility to scale up, down or change solutions
  • Improve troubleshooting
  • Mix of best-in-class components from a variety of suppliers to optimize solutions
  • Gather and distribute IIoT data upwards to higher level systems

Many users are realizing that neither an Ethernet-based safety protocol, nor a device level safety protocol can meet all their needs, especially if they are trying to implement a cost-effective, comprehensive safety solution which can also support their IIoT needs. This is where a safety communications master (or bridge) comes in – it can connect a device level safety protocol to a control level safety protocol, allowing low cost sensor connection and data gathering at the device level, and transmission of this data to the higher-level communications and control system.

An example of this architecture is Safety Over IO-Link on PROFISafe/PROFINET. Devices such as safety light curtains, E-stops and safety switches are connected to a “Safety Hub” which has implemented the Safety Over IO-Link protocol. This hub communicates via a “black channel” over a PROFINET/IO-Link Master to a PROFISafe PLC. The safety device connections are very simple and inexpensive (off the shelf cables & standard M12 connectors), and the more expensive (and more capable) Ethernet (PROFINET/PROFISafe) connections are only made where they are needed: at the masters, PLCs and other control level devices. And an added benefit is that standard and safety sensors can both connect through the PROFINET/IO-Link Master, simplifying the device level architecture.

Safety

Combining device level and control level protocols helps users optimize their safety communications solutions, balancing cost, data and speed requirements, and allows IIoT data to be gathered and distributed upwards to control and MES systems.

 

Posted on

Industrial Safety Protocols

There are typically three or more communication levels in the modern factory which consist of:

  • Enterprise level (Ethernet)
  • Control level (Ethernet based industrial protocol)
  • Device/sensor level (various technologies)

IO-Link

The widespread use of control and device level communications for standard (non-safety) industrial applications led to a desire for similar communications for safety. We now have safety versions of the most popular industrial control level protocols, these make it possible to have safety and standard communications on the same physical media (with the appropriate safety hardware implemented for connectivity and control). In a similar manner, device level safety protocols are emerging to allow standard and safety communications over the same media. Safety Over IO-Link and AS-i Safety At Work are two examples.

This table lists the most common safety control level protocols with their Ethernet-based industrial “parent” protocols and the governing organizations:

chart1

And this table lists some of the emerging, more well-known, safety device level protocols with their related standard protocols and the governing or leading organizations:

Chart2
* Safety Over IO-Link is the first implementation of safety and IO-Link. The specification for IO-Link Safety was released recently and devices are not yet available.

Ethernet-based safety protocols are capable of high speed and high data transmission, they are ideal for exchanging data between higher level devices such as safety PLCs, drives, CNCs, HMIs, motion controllers, remote safety I/O and advanced safety devices. Device level protocol connections are physically smaller, much less expensive and do not use up IP addresses, but they also carry less data and cover shorter distances than Ethernet based protocols. They are ideal for connecting small, low cost devices such as E-stops, safety switches and simple safety light curtains.

As with standard protocols, neither a control level safety protocol, nor a device level safety protocol can meet all needs, therefore cost/performance considerations drive a “multi-level” communications approach for safety. This means a combined solution may be the best fit for many safety and standard communications applications.

A multi-level approach has many advantages for customers seeking a cost-effective, comprehensive safety and standard control and device solution which can also support their IIoT needs. Users can optimize their safety communications solutions, balancing cost, data and speed requirements.

Posted on

Increase Competitiveness with RFID in the Intralogistics Industry

In times of globalization and high labor costs it is a challenge to increase competitiveness in the fashion industry. Within a warehouse, an RFID system supports a high degree of automation as well as short transport distances. To supply dealers and to keep their facility profitable, one of the most successful fashion companies in the world has built a highly modern hanging garment distribution center. Let’s take a look at how they successfully implemented RFID technology to improve their processes.

Separate and sort clothes with just one hybrid module (2D code + RFID)

Within this distribution center 45,000 of these innovative clothes hanger adapters (L-VIS) are used. They replace the previous trolley-based logistics approach by allowing the transportation of a number of different garments that have the same destination.

OLYMPUS DIGITAL CAMERA
L-VIS, clothes hanging adapter made by P.E.P. Fördertechnik

With the investment in some additional space in the so-called buffer or storage zone, and by providing empty trolleys at various locations to keep the product flow moving, this project is successfully accomplished. A major advantage of this system, is the usability over the entire intralogistics chain. From receiving, to the hanging storage, to the sorter for single item identification, and from there as a transport unit to shipping.

The clothes hanger contains an RFID chip, that is automatically read by the conveying technology, and the 2D-code. This code is read manually by employees with a portable acquisition unit. The code can be DMC (Data Matrix Code), QR-Code, or any other optical code standard.

OLYMPUS DIGITAL CAMERA
HUGO BOSS garment distribution center (Metzingen, Germany)

Information exchange without visual contact

A high frequency RFID chip is installed. With this identification system, neither direct alignment nor contact is needed to enable data exchange via nearfield communication. Non-contact identification is extremely reliable and wear-free. The identification system consists of a rugged data carrier, a read/write head and an RFID processor unit. The processor unit communicates to the control system via Profibus, but could be accomplished with ProfiNet or EtherNet/IP as well.

OLYMPUS DIGITAL CAMERA
BIS-M RFID processor unit

The following table gives you an overview of types of Radio Frequency Identification solutions that are available on the market:

Common Types Low Frequency Low Frequency High Frequency Ultra High Frequency
Frequency 70/455 kHz 125 kHz 13.56 MHz 860 … 960 MHz
Short description Dedicated solution to tool identification in Metal-Working industry. Standard solutions for simple Track & Trace applications. Fast & reliable – even with high volumes of data in medium distances in assembly, production and intralogistics. Identification at large distances and bunching capability for current material flow concept.

For the customer, the decision to choose this particular system among others was the separation between the processor and read/write head. In a widespread facility it would not make sense to have a decoder with 30 read/write heads attached. By interfacing two read/write heads per processor, it is possible to track the travel of a transport unit over the entire conveyor line as well as track within the aisles between the individual shelves.

An additional advantage of the system implemented is the housing options. The L-VIS carrier and the 30 mm read/write head are an ideal match. The simple mounting of the processors and ready-to-use connection were of high value to the system integrators. In the sorting area, a 2D code was supplemented by the RFID tags to reach speeds of up to 0.6 and 0.7 m/s. This would probably not have been possible with the installation of a corresponding camera technology.

Experiences have shown, that RFID projects need a lot of support. Consultation and assistance from true experts can be provided by our team. Learn more about RFID technology here.

Posted on

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.

Posted on

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

Posted on

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.

Posted on

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.

Posted on

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.

Continue reading “2 Simple Ways to Protect from Arc Flash Hazards”