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Mastering IO-Link: Best Practices for Seamless Industrial Automation Integration

IO-Link is a versatile communication protocol for use in industrial automation to connect sensors and actuators to control systems. Here are some best practices to consider when implementing IO-Link in your automation setup:

Device selection: Choose IO-Link devices that best fit your application’s requirements. Consider factors such as sensing range, accuracy, ruggedness, and compatibility with your IO-Link master and network. Look to see if add-on Instructions and/or function blocks are available for ease of integration.

Network topology: Design a clear and well-organized network topology. Plan the arrangement of IO-Link devices, masters, and other components to minimize cable lengths and optimize communication efficiency. Remember that the maximum distance for an IO-Link device is 20 meters of cable from the IO-Link master.

Standardized cable types: Use standardized IO-Link cables to ensure consistent and reliable connections. High-quality cables can prevent signal degradation and communication issues. Pay careful attention to the needs of the IO-Link device. Some devices require 3, 4, or 5 conductors in the associated cable.

Parameterization and configuration: Take advantage of IO-Link’s ability to remotely configure and parameterize devices. This simplifies setup and makes it possible to change device settings without physically accessing the device. Learn how to take advantage of the IO-Link master’s parameter server functionality.

Centralized diagnostics: Use the diagnostic capabilities of IO-Link devices to monitor health, status, and performance. Centralized diagnostics can help identify issues quickly and enable predictive maintenance. Of the three types of IO-Link data, pay attention to the event data.

Remote monitoring and control: Leverage IO-Link’s bi-directional communication to remotely monitor and adjust devices. This can improve operational efficiency by reducing the need for manual intervention.

Error handling: Implement error handling mechanisms to respond to communication errors or device failures. This could include notifications, alarms, and fallback strategies.

Network segmentation: If you have a large and complex automation setup, consider segmenting your IO-Link network into smaller sections. This can help manage network traffic and improve overall performance.

Training and documentation: Provide training for your team on IO-Link technology, best practices, and troubleshooting techniques. Create documentation that outlines network layouts, device addresses, and configuration details.

Testing and validation: Thoroughly test IO-Link devices and their interactions before deploying them in a production environment. This can help identify potential issues and ensure proper functionality.

Scalability: Plan for future expansion by designing a scalable IO-Link network. Consider how easily you can add new devices or reconfigure existing ones as your automation needs evolve.

Vendor collaboration: Collaborate closely with IO-Link device manufacturers and IO-Link master suppliers. They can provide valuable insights and support during the planning, implementation, and maintenance stages.

By following these best practices, you can optimize the implementation of IO-Link in your industrial automation setup, leading to improved efficiency, reliability, and ease of maintenance.

Click here to learn more about using IO-Link to improve process quality.

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From Wired to Wireless Automation Advancements in Automotive Manufacturing

Looking back, the days of classic muscle cars stand out as a remarkable period in automotive history. Consider how they were built, including every component along the assembly line connected through intricate wiring, resulting in prolonged challenges related to both wiring and maintenance. Advancements in technology led to the introduction of junction blocks, yet this didn’t entirely solve the persistent problems associated with time and connections.

In the mid-2000s, a collaborative effort among multiple companies resulted in the development of the IO-Link protocol. This protocol effectively tackled the wiring and maintenance issues. Since its inception, IO-Link has continued to progress and evolve.

In 2023, we’re taking the next step with a wireless IO-Link master block.

In modern manufacturing, the process involves using independently moving automated guided vehicles (AGVs), also known as skillets. These AGVs are responsible for performing various tasks along the production line before completing their circuit and returning to their initial position. Initially, when these AGVs were integrated, each of these skillets was equipped with a programmable logic controller (PLC), which incurred significant expenses and extended the setup time. Additionally, the scalability of this system was limited by the available IP addresses for the nodes.

Demand for wireless IO-Link blocks

In recent years, there has been a growing demand for wireless IO-Link blocks. Now, a solution to meet this demand is available. The wireless IO-Link block works in a manner similar to the existing current blocks but without the need for a PLC, simplifying wiring and using existing Wi-Fi infrastructure.

Imagine a conveyor scenario where numerous AGVs follow a designated path, each with a hub attached. The setup would look something like this: up to 40 hubs communicating simultaneously with a central master. Each hub has the capacity to accommodate up to eight connected devices, resulting in a total of 320 distinct IO points managed by a single IO-Link master.

Communication among these blocks employs a protocol akin to that of a cell phone. As an AGV transitions from one master hub to another, it continues to transmit its data. Within each hub, an identity parameter not only designates the specific hub but also identifies the associated skillets and the location within the manufacturing plant.

Transitioning to a wireless system leads to a substantial reduction in your overall cost of ownership. This includes decreased setup times, simplified troubleshooting, lower maintenance efforts, and a reduced need for spare parts.

We are in an exciting time of technological advancement. Make sure you are moving alongside us!

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Comparing IO-Link and Modbus Protocols in Industrial Automation

In the realm of industrial automation, the seamless exchange of data between sensors, actuators, and control systems is critical for optimizing performance, increasing efficiency, and enabling advanced functionalities. Two widely used communication protocols, IO-Link and Modbus, have emerged to facilitate this data exchange. In this blog, I’ll analyze the characteristics, strengths, and weaknesses of both protocols to help you choose the right communication standard for your industrial application.

IO-Link: transforming industrial communication for advanced applications

IO-Link is a relatively new communication protocol designed to provide seamless communication between sensors and actuators and the control system. It operates on a point-to-point communication model, meaning each device on the network communicates directly with the IO-Link master or gateway. IO-Link offers features like bidirectional process data exchange, parameterization, device diagnostics, and plug-and-play functionality, making it an ideal choice for advanced industrial applications.

IO-Link key features:

    • Bidirectional communication: IO-Link allows data exchange not only from the IO-Link master to the devices but also from devices to the IO-Link master, enabling real-time diagnostics and enhanced control.
    • Device parameterization: IO-Link supports remote device configuration, reducing downtime during device replacement or maintenance.
    • Diagnostics: The protocol provides extensive diagnostic capabilities, allowing for proactive maintenance and minimizing production interruptions, including condition monitoring.
    • Flexibility: IO-Link supports a plethora of smart devices, both digital and analog devices, signal converters, and condition monitoring sensors, providing compatibility with a wide range of sensors and actuators, and is manufacturer-independent.

Modbus: a time-tested protocol power industrial communication

Modbus is a widely adopted communication protocol introduced in the late 1970s. Initially designed for serial communication, it has evolved and now includes TCP/IP-based versions for Ethernet networks. Modbus operates on a master-slave architecture, where a single master device communicates with multiple slave devices. Due to its simplicity and ease of implementation, Modbus remains popular in many industrial applications.

Modbus key features:

    • Simplicity: Modbus is a straightforward protocol, making it easy to implement, and troubleshoot, especially in smaller networks.
    • Versatility: Modbus can be used over various physical communication media, including serial (RS-232/RS-485) and Ethernet (TCP/IP).
    • Widely supported: A vast array of devices and system support Modbus due to its long-standing presence in the industry.
    • Low overhead: Modbus has minimal message overhead, making it suitable for simple and time-critical applications.

Now, let’s compare IO-Link and Modbus based on several crucial factors:

    • Speed and data capacity:

   – IO-Link offers higher data transfer rates, making it suitable for applications requiring real-time data exchange and high precision.

– Modbus operates at lower speeds, limiting its suitability for applications with demanding data transfer requirements.

    • Complexity and configuration:

   – IO-Link’s advanced features may require more complex configuration and setup, but its bidirectional communication, device parameterization capabilities, and remote diagnostics make it more versatile.

   – Modbus’ simplicity makes it easier to configure and deploy, but it lacks the bidirectional communication and parameterization features found in IO-Link.

    • Device compatibility:

   – IO-Link’s compatibility with both digital and analog smart devices, and being manufacturer-independent, ensures a much broader range of sensor and actuator support.

   – Modbus is compatible with various devices, but its support for analog devices can be limited in comparison to IO-Link.

    • Diagnostics and maintenance:

   – IO-Link’s comprehensive diagnostics facilitate proactive maintenance and rapid issue resolution.

   – Modbus provides basic diagnostics, but they may not be as extensive or real-time as those offered by IO-Link.

    • Industry adoption:

   – IO-Link adoption is growing in industrial automation, especially in applications that demand high performance, advanced capabilities, and support of IIOT.

   – Modbus has been widely adopted over the years and remains prevalent, especially in legacy systems or simpler applications.

Both IO-Link and Modbus are valuable communication protocols in industrial automation, each with its strengths and weaknesses. IO-Link excels in high-performance applications that demand real-time data exchange, bidirectional communication, and advanced diagnostics. On the other hand, Modbus remains a viable option for simpler systems where ease of implementation and broad device support are essential.

The choice between IO-Link and Modbus depends on the specific requirements of your industrial application, the level of complexity needed, and the devices you plan to use. Understanding the capabilities of each protocol will empower you to make an informed decision, ensuring your communication system optimally supports your automation needs.

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Revisiting the Key Points of IO-Link

IO-Link is a communication protocol for use in industrial automation systems to connect sensors and actuators to a central control system. It provides a standardized interface for the communication and configuration of devices, allowing for seamless integration and easy parameterization.

Here are some key points about IO-Link

    • Communication: IO-Link uses a point-to-point serial communication link between the IO-Link master and the IO-Link devices (sensors or actuators). Typically, the communication occurs over a standard 3-wire sensor cable.
    • Master/device architecture: The IO-Link system consists of an IO-Link master, which serves as a gateway between the IO-Link devices and the control system. The IO-Link master can connect to multiple IO-Link devices in a network.
    • Device identification: On the network, each IO-Link device uniquely identifies itself. When the devices connect to the IO-Link master, it automatically recognizes the device and communicates its parameters and capabilities to the master.
    • Configuration and parameterization: IO-Link allows for easy configuration and parameterization of connected devices. Through the master, the control system can read and write device parameters, such as sensor ranges, output behavior, and diagnostic information.
    • Data exchange: IO-Link supports the exchange of process data, event data, and service data. Process data is the primary information exchanged between the device and the control system primarily exchange process data, which represents the measured or controlled variables. Status and diagnostic information make up the event data, while configuration and parameterization use the service data.

Overall, IO-Link offers a flexible and standardized communication platform for connecting sensors and actuators in industrial automation systems. Its ease of use, configurability, and diagnostic capabilities make it a popular choice for modern industrial applications.

Click here for some IO-Link application examples.

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Automated Welding With IO-Link

IO-Link technologies have been a game-changer for the welding industry. With the advent of automation, the demand for increasingly sophisticated and intelligent technologies has increased. IO-Link technologies have risen to meet this demand. Here I explain the concepts and benefits of I-O Link technologies and how they integrate into automated welding applications.

What are IO-Link technologies?

IO-Link technologies refer to an advanced communication protocol used in industrial automation. The technology allows data transfer, i.e., the status of sensors, actuators, and other devices through a one-point connection between the control system and individual devices. Also, it enables devices to communicate among themselves quickly and efficiently. IO-Link technologies provide real-time communication, enabling continuous monitoring of devices to ensure optimal performance.

Benefits of IO-Link technologies

    • Enhanced data communication: IO-Link technologies can transfer data between the control system and sensors or devices. This communication creates an open and transparent network of information, reflecting the real-time status of equipment and allowing for increased reliability and reduced downtime.
    • Cost-efficiency: IO-Link technologies do not require complicated wiring and can significantly reduce material costs compared to traditional hardwired solutions. Additionally, maintenance is easier and more efficient with communication between devices, and there is less need for multiple maintenance employees to manage equipment.
    • Flexibility: With IO-Link technologies, the control system can control and monitor devices even when not attached to specific operator workstations. It enables one control system to manage thousands of devices without needing to rewrite programming to accommodate different machine types.
    • Real-time monitoring: IO-Link technologies provide real-time monitoring of devices, allowing control systems to monitor failures before they occur, making it easier for maintenance teams to manage the shop floor.

How are IO-Link technologies used in automated welding applications?

Automated welding applications have increased efficiencies and continuity in processes, and IO-Link technologies have accelerated these processes further. Automated welding applications have different stages, and each step requires real-time monitoring to ensure the process is efficient and effective. IO-Link technologies have been integrated into various parts of the automated welding process, some of which include:

    1. Positioning and alignment: The welding process starts with positioning and aligning materials such as beams, plates, and pipes. IO-Link sensors can detect the height and gap position of the material before the welding process begins. The sensor sends positional data to the control system as a feedback loop, which then adjusts the positioning system using actuators to ensure optimal weld quality.
    2. Welding arc monitoring: The welding arc monitoring system is another critical application for IO-Link technologies. Monitoring the arc ensures optimal weld quality and runs with reduced interruptions. IO-Link temperature sensors attached to the welding tip help control and adjust the temperature required to melt and flow the metal, ensuring that the welding arc works optimally.
    3. Power supply calibration: IO-Link technologies are essential in calibrating the power output of welding supplies, ensuring consistent quality in the welding process. Detectors attached to the power supply record the energy usage, power output and voltage levels, allowing the control system to adjust as necessary.
    4. Real-time monitoring and alerting: Real-time monitoring and alerting capabilities provided by IO-Link technologies help to reduce downtime where machine health is at risk. The sensors monitor the welding process, determining if there are any deviations from the set parameters. They then communicate the process condition to the control system, dispatching alerts to maintenance teams if an issue arises.

Using IO-Link technologies in automated welding applications has revolutionized the welding industry, providing real-time communication, enhanced data transfer, flexibility, and real-time monitoring capabilities required for reliable processes. IO-Link technologies have been integrated at various stages of automated welding, including positioning and alignment, welding arc monitoring, power supply calibration, and real-time monitoring and alerting. There is no doubt that the future of automated welding is bright. With IO-Link technologies, the possibilities are endless, forging ahead to provide more intelligent, efficient, and reliable welding applications.

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Why Choose an IO-Link Ecosystem for Your Next Automation Project?

By now we’ve all heard of IO-Link, the device-level communication protocol that seems magical. Often referred to as the “USB of industrial automation,” IO-Link is a universal, open, and bi-directional communication technology that enables plug-and-play device replacement, dynamic device configuration, centralized device management, remote parameter setting, device level diagnostics, and uses existing sensor cabling as part of the IEC standard accepted worldwide.

But what makes IO-Link magical?

If the list above doesn’t convince you to consider using IO-Link on your next automation project, let me tell you more about the things that matter beyond its function as a communications protocol.

Even though these benefits are very nice, none of them mean anything if the devices connected to the network don’t provide meaningful, relevant, and accurate data for your application.

Evolution of the IO-Link

IO-Link devices, also known as “smart devices,” have evolved significantly over the years. At first, they were very simple and basic, providing data such as the status of your inputs and outputs and maybe giving you the ability to configure a few basic parameters, such as port assignment as an input or an output digitally over IO-Link. Next, came the addition of functions that would improve the diagnostics and troubleshooting of the device. Multi-functionality followed, where you have one device under one part number, and can configure it in multiple modes of operation.

Nothing, however, affected the development of smart devices as much as the introduction of IIoT (Industrial Internet of Things) and the demand for more real-time information about the status of your machine, production line, and production plant starting at a device level. This demand drove the development of smart devices with added features and benefits that are outside of their primary functions.

Condition monitoring

IO-Link supplies both sensor/actuator details and secure information
IO-Link supplies both sensor/actuator details and secure information

One of the most valuable added features, for example, is condition monitoring. Information such as vibration, humidity, pressure, voltage and current load, and inclination – in addition to device primary function data – is invaluable to determine the health of your machine, thus the health of your production line or plant.

IO-Link offers the flexibility to create a controls architecture independent of PLC manufacturer or higher-level communications protocols. It enables you to:

    • use existing low-cost sensor cabling
    • enhance your existing controls architecture by adding devices such as RFID readers, barcode and identification vision sensors, linear and pressure transducers, process sensors, discrete or analog I/O, HMI devices, pneumatic and electro-mechanical actuators, condition monitoring, etc.
    • dynamically change the device configuration, auto-configure devices upon startup, and plug-and-play replacement of devices
    • enable IIOT, predictive maintenance, machine learning, and artificial intelligence

There is no other device-level communications protocol that provides as many features and benefits and is cost-effective and robust enough for industrial automation applications as IO-Link.

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Automation Insights: Top Blogs From 2022

It’s an understatement to say 2022 had its challenges. But looking back at the supply chain disruptions, inflation, and other trials threatening success in many industries, including manufacturing, there were practical insights we can benefit from as we dive into 2023. Below are the most popular blogs from last year’s Automation Insights site.

    1. Evolution of Pneumatic Cylinder Sensors

Top 2022 Automation Insights BlogsToday’s pneumatic cylinders are compact, reliable, and cost-effective prime movers for automated equipment. They’re used in many industrial applications, such as machinery, material handling, assembly, robotics, and medical. One challenge facing OEMs, integrators, and end users is how to detect reliably whether the cylinder is fully extended, retracted, or positioned somewhere in between before allowing machine movement.

Read more.

    1. Series: Condition Monitoring & Predictive Maintenance 

Top 2022 Automation Insights BlogsBy analyzing which symptoms of failure are likely to appear in the predictive domain for a given piece of equipment, you can determine which failure indicators to prioritize in your own condition monitoring and predictive maintenance discussions.

Read the series, including the following blogs:

    1. Know Your RFID Frequency Basics

Top 2022 Automation Insights BlogsIn 2008 I purchased my first toll road RFID transponder, letting me drive through and pay my toll without stopping at a booth. This was my first real-life exposure to RFID, and it was magical. Back then, all I knew was that RFID stood for “radio frequency identification” and that it exchanged data between a transmitter and receiver using radio waves. That’s enough for a highway driver, but you’ll need more information to use RFID in an industrial automation setting. So here are some basics on what makes up an RFID system and the uses of different radio frequencies.

Read more.

    1. IO-Link Event Data: How Sensors Tell You How They’re Doing

Top 2022 Automation Insights BlogsI have been working with IO-Link for more than 10 years, so I’ve heard lots of questions about how it works. One line of questions I hear from customers is about the operating condition of sensors. “I wish I knew when the IO-Link device loses output power,” or, “I wish my IO-Link photoelectric sensor would let me know when the lens is dirty.” The good news is that it does give you this information by sending Event Data. That’s a type of data that is usually not a focus of users, although it is available in JSON format from the REST API.

Read more.

    1. Converting Analog Signals to Digital for Improved Performance

Top 2022 Automation Insights BlogsWe live in an analog world, where we experience temperatures, pressures, sounds, colors, etc., in seemingly infinite values. There are infinite temperature values between 70-71 degrees, for example, and an infinite number of pressure values between 50-51 psi.

Read more.

We appreciate your dedication to Automation Insights in 2022 and look forward to growth and innovation in 2023.

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IO-Link Changeover: ID Without RFID – Hub ID

When looking at flexible manufacturing, what first comes to mind are the challenges of handling product changeovers. It is more and more common for manufacturers to produce multiple products on the same production line, as well as to perform multiple operations in the same space.

Accomplishing this and making these machines more flexible requires changing machine parts to allow for different stages in the production cycle. These interchangeable parts are all throughout a plant: die changes, tooling changes, fixture changes, end-of-arm tooling, and more.

When swapping out these interchangeable parts it is crucial you can identify what tooling is in place and ensure that it is correct.

ID without RFID

When it comes to identifying assets in manufacturing today, typically the first option companies consider is Radio-Frequency Identification (RFID). Understandably so, as this is a great solution, especially when tooling does not need an electrical connection. It also allows additional information beyond just identification to be read and written on the tag on the asset.

It is more and more common in changeover applications for tooling, fixtures, dies, or end-of-arm tooling to require some sort of electrical connection for power, communication, I/O, etc. If this is the case, using RFID may be redundant, depending on the overall application. Let’s consider identifying these changeable parts without incurring additional costs such as RFID or barcode readers.

Hub ID with IO-Link

In changeover applications that use IO-Link, the most common devices used on the physical tooling are IO-Link hubs. IO-Link system architectures are very customizable, allowing great flexibility to different varieties of tooling when changeover is needed. Using a single IO-Link port on an IO-Link master block, a standard prox cable, and hub(s), there is the capability of up to: 

    • 30 Digital Inputs/Outputs or
    • 14 Digital Inputs/Outputs and Valve Manifold Control or
    • 8 Digital Inputs/Outputs and 4 Analog Voltage/Current Signals or
    • 8 Analog Input Signals (Voltage/Current, Pt Sensor, and Thermocouple)

When using a setup like this, an IO-Link 1.1 hub (or any IO-Link 1.1 device) can store unique identification data. This is done via the Serial Number Parameter and/or Application Specific Tag Parameter. They act as a 16- or 32-byte memory location for customizable alphanumeric information. This allows for tooling to have any name stored within that memory location. For example, Fixture 44, Die 12, Tool 78, EOAT 123, etc. Once there is a connection, the controller can request the identification data from the tool to ensure it is using the correct tool for the upcoming process.

By using IO-Link, there are a plethora of options for changeover tooling design, regardless of various I/O requirements. Also, you can identify your tooling without adding RFID or any other redundant hardware. Even so, in the growing world of Industry 4.0 and the Industrial Internet of Things, is this enough information to be getting from your tooling?

In addition to the diagnostics and parameter setting benefits of IO-Link, there are now hub options with condition monitoring capabilities. These allow for even more information from your tooling and fixtures like:

    • Vibration detection
    • Internal temperature monitoring
    • Voltage and current monitoring
    • Operating hours counter

Flexible manufacturing is no doubt a challenge and there are many more things to consider for die, tooling and fixture changes, and end-of-arm tooling outside of just ID. Thankfully, there are many solutions within the IO-Link toolbox.

For your next changeover, I recommend checking out Non-Contact Inductive Couplers Provide Wiring Advantages, Added Flexibility and Cost Savings Over Industrial Multi-Pin Connectors for a great solution for non-contact connectivity that can work directly with Hub ID.

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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?

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IO-Link Event Data: How Sensors Tell You How They’re Doing

I have been working with IO-Link for more than 10 years, so I’ve heard lots of questions about how it works. One line of questions I hear from customers is about the operating condition of sensors. “I wish I knew when the IO-Link device loses output power,” or, “I wish my IO-Link photoelectric sensor would let me know when the lens is dirty.” The good news is that it does give you this information by sending Event Data. That’s a type of data that is usually not a focus of users, although it is available in JSON format from the REST API.

There are three types of IO-Link data:

      • Process Data – updated cyclically, it’s important to users because it contains the data for use in the running application, like I/O change of states or measurement values like temperature and position, etc.
      • Parameter Data – updated acyclically, it’s important to users because it’s the mechanism to read and write parameter values like setpoints, thresholds, and configuration settings to the sensor, and for reading non-time critical values like operating hours, etc.
      • Event Data – updated acyclically, it’s important to users because it provides immediate updates on device conditions.

Let’s dig deeper into Event Data. An Event is a status update from the IO-Link device when a condition is out of its normal range. The Event is labeled as a Warning or Error based on the severity of the condition change.

When an Event occurs on the IO-Link device, the device sets the Event Flag bit in the outgoing data packet to the IO-Link Master. The Master receives the Event Flag and then queries the IO-Link device for the Event information.

It is important to note that this is a one-time data message. The IO-Link device only sends the Event Flag at the moment the condition is out of range, and then again when the condition is back in range.

Event Data Types, Modes, and Codes

Event Data has three following three components:

      • Event Type – categorized in three ways
        • Notification – a simple event update; nothing is abnormal with the IO-Link device
        • Warning – a condition is out of range and risks damaging the IO-Link device
        • Error – a condition is out of range and is affecting the device negatively to the point that it may not function as expected
      • Event Mode – categorized in three ways
        • Event notice – usually associated with Event Type notifications, message will not be updated
        • Event appears – the condition is now out of range
        • Event disappears – the condition is now back in range
      • Event Code
        • A two-byte Hex code that represents the condition that is out of range

IO-Link condition monitoring sensor

To bring all these components together, let’s look at a photoelectric IO-Link sensor with internal condition monitoring functions and see what Events are available for it in this device manual screenshot. This device has Events for temperature (both warning and error), voltage, inclination (sensor angle is out of range), vibration, and signal quality (dirty lens).

By monitoring these events, you have a better feel for the conditions of your IO-Link device. Along with helping you identify immediate problems, this can help you in planning preventive and planned maintenance.

An IO-Link condition monitoring sensor uses Event Data similarly to report when conditions exceed the thresholds that you have set. For example, when the vibration level exceeds the threshold value, the IO-Link device sends the Warning event flag and the IO-Link Master queries for the event data. The event data consists of an Event Type, an Event Mode, and an Event Code that represents the specific alarm condition that is out of range. Remember this is a one-time action; the IO-Link sensor will not report this again until the value is in an acceptable range.

When the vibration level is back in range, the alarm condition is no longer present in the IO-Link device, the process repeats itself. In this case the Event Type and Event Code will be the same. The only change is that the Event Mode will report Event Disappears.

Within the IO-Link Specification there is a list of defined Event Codes that are common across all vendors. There is also a block of undefined Event Code values that allow vendors to create Event Codes that are unique to their specific device.

“I wish the IO-Link device would let me know….” In the end, the device might be telling you what you want to know, especially if the device has condition monitoring functions built into it. If you want to know more about condition monitoring in your IO-Link devices, check out the Event section in the vendor’s manuals so you can learn how to use this information.