IO-Link vs. Analog in Measurement Applications

IO-Link is well-suited for use in measurement applications that have traditionally used analog (0…10V or 4…20mA) signals. This is thanks in large part to the implementation of IO-Link v1.1, which provides faster data transmission and increased bandwidth compared to v1.0. Here are three areas where IO-Link v1.1 excels in comparison to analog.

1

Fewer data errors, at lower cost

By nature, analog signals are susceptible to interference caused by other electronics in and around the equipment, including motors, pumps, relays, and drives. Because of this, it’s almost always necessary to use high-quality, shielded cables to transmit the signals back to the controller. Shielded cables are expensive and can be difficult to work with. And even with them in place, signal interference is a common issue that is difficult to troubleshoot and resolve.

2

With IO-Link, measurements are converted into digital values at the sensor, before transmission. Compared to analog signals, these digital signals are far less susceptible to interference, even when using unshielded 4-wire cables which cost about half as much as equivalent shielded cables. The sensor and network master block (Ethernet/IP, for example) can be up to 20 meters apart. Using industry-standard connectors, the possibility for wiring errors is virtually eliminated.

3

Less sensor programming required

An analog position sensor expresses a change in position by changing its analog voltage or current output. However, a change of voltage or current does not directly represent a unit of measurement. Additional programming is required to apply a scaling factor to convert the change in voltage or current to a meaningful engineering unit like millimeters or feet.

It is often necessary to configure analog sensors when they are being installed, changing the default characteristics to suit the application. This is typically performed at the sensor itself and can be fairly cumbersome. When a sensor needs to be replaced, the custom configuration needs to be repeated for the replacement unit, which can prolong expensive machine downtime.

IO-Link sensors can also be custom configured. Like analog sensors, this can be done at the sensor, but configuration and parameterization can also be performed remotely, through the network. After configuration, these custom parameters are stored in the network master block and/or offline. When an IO-Link sensor is replaced, the custom parameter data can be automatically downloaded to the replacement sensor, maximizing machine uptime.

Diagnostic data included

A major limitation of traditional analog signals is that they provide process data (position, distance, pressure, etc.) without much detail about the device, the revision, the manufacturer, or fault codes. In fact, a reading of 0 volts in a 0-10VDC interface could mean zero position, or it could mean that the sensor has ceased to function. If a sensor has in fact failed, finding the source of the problem can be difficult.

With IO-Link, diagnostic information is available that can help resolve issues quickly. As an example, the following diagnostics are available in an IO-Link magnetostrictive linear position sensor: process variable range overrun, measurement range overrun, process variable range underrun, magnet number change, temperature (min and max), and more.

4

This sensor level diagnostic information is automatically transmitted and available to the network, allowing immediate identification of sensor faults without the need for time-consuming troubleshooting to identify the source of the problem.

To learn about the variety of IO-Link measurement sensors available, read the Automation Insights post about ways measurement sensors solve common application challenges. For more information about IO-Link and measurement sensors, visit www.balluff.com.

Set your sights on IO-Link for machine vision products

While IO-Link is well addressed in an automated production environment, some have overlooked the benefits IO-Link can deliver for machine vision products.

PLC Gateway-Modus

Any IO-Link device can be connected and controlled by the PLC via fieldbus interface. Saving installation costs and controlling and running IO-Link components are the key values. All the well-known IO-Link benefits apply.

Rainer1

Camera-Modus – without PLC

However, with IO-Link that operates in this mode, the IO-Link-interfaces Rainer2are directly controlled. IO-Link I/O-Modules are automatically detected, configured and controlled.

In a stand-alone situation where an optical inspectionRainer3 of a component is performed without PLC, the operator delivers the component, hits a trigger button, the SmartCamera checks for completeness of production quality, sends a report to a separate customer server, and controls directly via IO-Link interface the connected vision product.

For more information about machine vision and optical identification see www.balluff.com

 

Reviewing options for optimized level detection in the food & beverage industry

Level detection plays an important role in the food and beverage industry, both in production and filling. Depending on the application, there are completely different requirements for level detection and, therefore, different requirements for the technologies and sensors to solve each task.

In general, we can differentiate between two requirements — Do I want to continuously monitor my filling level so that I can make a statement about the current level at any time? Or do I want to know if my filling level has reached the minimum or maximum?

Let’s look at both requirements and the appropriate level sensors and technologies in detail.

Precisely detecting point levels

For point level detection we have three different options.

A through-beam fork sensor on the outside of the tank is well suited for transparent container walls and very special requirements. Very accurate and easy to install, it is a good choice for critical filling processes while also being suitable for foaming materials.

Image 1
One point level detection through transparent container walls

For standard applications and non-metallic tank walls, capacitive sensors, which can be mounted outside the tank, are often the best choice. These sensors work by detecting the change of the relative electric permittivity. The measurement does not take place in direct contact with the medium.

Figure 2
Minimum/maximum level detection with capacitive sensors

For applications with metal tanks, there are capacitive sensors, which can be mounted inside the tank. Sensors, which meet the special requirements for cleanability (EHEDG, IP69K) and food contact material (FCM) required in the food industry,  are mounted via a thread and a sealing element inside the tank. For conductive media such as ketchup, specially developed level sensors can be used which ignore the adhesion to the active sensor surface.

Figure 3
Capacitive sensors mounted inside the tank

Continuous level sensing

Multiple technologies can be used for continuous level sensing as well. Choosing the best one depends on the application and the task.

Continuous level detection can also be solved with the capacitive principle. With the aid of a capacitive adhesive sensor, the level can be measured from the outside of the tank without any contact with the sensor. The sensor can be easily attached to the tank without the use of additional accessories. This works best for tanks up to 850 mm.

Figure 4
Continuous level detection with a capacitive sensor head

If you have fast and precise filling processes, the magnetostrictive sensing principle is the right choice. It offers very high measuring rate and accuracy. It can be used for tank heights from 200 mm up to several meters. Made especially for the food and beverage  industry, the sensor has the Ecolab, 3A and FDA certifications. Thanks to corrosion-free stainless steel, the sensor is safe for sterilization (SIP) and cleaning (CIP) in place.

Figure 5
Level detection via magnetostrictive sensing principle

If the level must be continuously monitored from outside the tank, hydrostatic pressure sensors are suitable. Available with a triclamp flange for hygienic demands, the sensor is mounted at the bottom of the tank and the level is indirectly measured through the pressure of the liquid column above the sensor.

Figure 6
Level detection via hydrostatic pressure sensor

Level detection through ultrasonic sensors is also perfect for the hygienic demands in the food industry. Ultrasonic sensors do not need a float, are non-contact and wear-free, and installation at the top of the tank is easy. Additionally, they are insensitive to dust and chemicals. There are even sensors available which can be used in pressurized tanks up to 6 bar.

Figure 7
Level detection via ultrasonic sensor

Product bundle for level monitoring in storage tanks

On occasion, both types of level monitoring are required. Take this example.

The tanks in which a liquid is stored at a food manufacturer are made of stainless steel. This means the workers are not able to recognize whether the tanks are full or empty, meaning they can’t tell when the tanks need to be refilled to avoid production downtime.

The solution is an IO-Link system which consists of different filling sensors and a light to visualize the filling level. With the help of a pressure sensor attached to the bottom of the tanks, the level is continuously monitored. This is visualized by a machine light so that the employee can see how full the tank is when passing by. The lights indicate when the tank needs to be refilled, while a capacitive sensor indicates when the tank is full eliminating overfilling and material waste.

Figure 8
Level monitoring in storage tanks

To learn more about solutions for level detection visit balluff.com

Changing the Paradigm from Safety vs. Productivity to Safety & Productivity

In a previous blog, we discussed how “Safety Over IO-Link Helps Enable Human-Robot Collaboration”. It was a fairly narrow discussion of collaborative robot modes and how sensors and networks can make it easier to implement these modes and applications. This new blog takes a broader look at the critical role safety plays in the intersection between the machine and the user.

In the past, the machine guarding philosophy was to completely separate the human from the machine or robot.  Unfortunately, this resulted in the paradigm of “safety vs. productivity” — you either had safety or productivity, but you couldn’t have both. This paradigm is now shifting to “safety & productivity”, driven by a combination of updated standards and new technologies which allow closer human-machine interaction and new modes of collaborative operation.

Tom_Safety1.pngThe typical machine/robot guarding scheme of the past used fences or hard guards to separate the human from the machine.  Doors were controlled with safety interlock switches, which required the machine to stop on access, such as to load/unload parts or to perform maintenance or service, and this reduced productivity.  It was also not 100% effective because workers inside a machine area or work cell might not be detected if another worker restarted the stopped machine.  Other drawbacks included the cost of space, guarding, installation, and difficultly changing the work cell layout once hard guarding had been installed.

We’ve now come to an era when our technology and standards allow improved human access to the machine and robot cell.  We’re starting to think about the human working near or even with the machine/robot. The robot and machinery standards have undergone several changes in recent years and now allow new modes of operation.  These have combined with new safety technologies to create a wave of robot and automation suppliers offering new robots, controllers, safety and other accessories.

Standards
Machine and robot safety standards have undergone rapid change in recent years. Standard IEC 61508, and the related machinery standards EN/ISO 13849-1 and EN/IEC 62061, take a functional approach to safety and define new safety performance levels. This means they focus more on the functions needed to reduce each risk and the level of performance required for each function, and less on selection of safety components. These standards helped define, and made it simpler and more beneficial, to apply safety PLCs and advanced safety components. There have also been developments in standards related to safe motion (61800-5-2) which now allow more flexible modes of motion under closely controlled conditions. And the robot standards (10218, ANSI RIA 15.06, TS15066) have made major advances to allow safety-rated soft axes, space limiting and collaborative modes of operation.

Technology
On the technology side, innovations in sensors, controllers and drives have changed the way humans interact with machines and enabled much closer, more coordinated and safer operation. Advanced sensors, such as safety laser scanners and 3D safety cameras, allow creation of work cells with zones, which makes it possible for an operator to be allowed in one zone while the robot performs tasks in a different zone nearby. Controllers now integrate PLC, safety, motion control and other functions, allowing fast and precise control of the process. And drives/motion systems now operate in various modes which can limit speed, torque, direction, etc. in certain modes or if someone is detected nearby.

Sensors and Networks
The monitoring of these robots, machines and “spaces” requires many standard and safety sensors, both inside and outside the machine or robot. But having a lot of sensors does not necessarily allow the shift from “productivity vs. safety” to “productivity & safety” — this requires a closely coordinated and integrated system, including the ability to monitor and link the “restricted space” and “safeguarded space.” This is where field busses and device-level networks can enable tight integration of devices with the control system. IO-Link masters and Safety Over IO-Link hubs allow the connection of a large number of devices to higher level field busses (ProfiNet/ProfiSafe) with effortless device connection using off-the-shelf, non-shielded cables and connectors.

Balluff offers a wide range of solutions for robot and machine monitoring, including a broad safety device portfolio which includes safety light curtains, safety switches, inductive safety sensors, an emergency stop device and a safety hub. Our sensors and networks support the shift to include safety without sacrificing productivity.

IO-Link Master Differences – Part 3

In the first part of this series “Demystifying Class A and Class B Type IO-Link Ports” we discussed the two different types of IO-Link master ports and pointed out how they differ in operation and applications. The point of that blog was to ensure that when we choose one over the other, what is the opportunity cost of that decision.

In my recent blog, part #2 in this series, “Not all IO-Link Masters are Born Equal!“, we explored that even when multiple vendors provide or call out their IO-Link master, they are different in the implementation of features and functions they offer. IO-Link is IO-Link! It is a standard for communication but other features that accompany the communication differentiates how they behave; for example- sensor only master, hybrid master, and architecture backbone master.

In this blog, we will focus on various implementations of Port Type A (or Class A) and how they add varying degrees of value to your applications.

Implementation #1: Figure 1 below depicts the guts (electrical connections) of one of the three implementations of the IO-Link Class A master port. Two key things to notice here:

  • The power coming into the IO-Link master port is only device power. There is no output power with this implementation. The reason that it is designed like this is to only integrate sensor inputs.
  • Pin 1 and Pin 3 provide the device power and ground (common) to the IO-Link device, pin 4 is IO-Link communication. Pin 2 works as an input only for digital sensors like photo-eyes or prox switches. Basically, this port can be split to use one IO-Link sensor (pins 1, 3 and 4) and one standard ON/OFF sensor (pins 1,3, and 2).
Figure 1
Figure 1: Implementation 1 of Class-A IO-Link Master Port (The electrical drawings shown here are simplified for illustration only, the actual implementation drawings may be different)

Another alternate of this implementation is that some vendors may have another IO-Link connection on Pin 2. So, it serves to add 2 IO-Link devices off the same port. Unfortunately, I am not an expert to say whether this is according to the specification or not.

The Prso: Low power consumption and simplifies integrating smart sensors.

The Cons: By definition, a control system has both inputs and outputs – controlling “something” based on sensory inputs and logic. This implementation provides semi-standard implementation to the controls architecture. IO-Link promises unified communication across the plant floor not half of the plant floor. Characteristics of this type of master port would be max output current of about 250-300mA per port and about 2A per module (rated for up to 4A, if its carries UL).

Implementation #2: This implementation is a slight variation of the sensor only port (Implementation #1 above). It is achieved by adding an output capability for pin 2 on each port- shown in figure 2 below. It is important to note that although each port has output capability on pin 2, the output power is shared with the device power for the port. It implies that, in case of E-stop situations, where shutting off power to the valves/solenoids connected to pin 2 or an IO-Link device that requires an output power, the entire device power will be shut-off.  Basically, the state of the device connected to pin 2 and state of IO-Link devices connected on pin 4 will be lost or requires more elaborate approach (programming, testing and validation) in the controls side to handling these types of safety situations.

Figure 2
Figure 2: Implementation 2 of Class-A IO-Link Master Port (The electrical drawings shown here are simplified for illustration only, the actual implementation drawings may be different)

This type of implementation is commonly found on hybrid IO-Link master’s Class A (type A) port implementation.

The Pros: Flexibility to use pin 2 for input or output – standardized approach to all devices.

The Cons: Lack of ability to control the output power separate from the device power – causing variety of controls approaches (lots of precautions) when incorporating machine safety.

Implementation #3: This implementation offers the most flexibility in designing the controls architecture that utilizes IO-Link. Figure 3 depicts the implementation below.  In this case, the device power, as prior approaches, comes from pin 1 and pin 3 but pin 2 uses a separate power for output. The pin 2 on each of these ports can be used for input, output or to provide separate output power to the IO-Link devices. It is important to note that although pin 2 offers output power separate from the device power, the common/ground for this power is still tied to pin 3. The output power is separate but not isolated, like in the Class B port implementation discussed in the blog “Demystifying Class A and Class B Type IO-Link Ports“.

Figure 3
Figure 3: Implementation 3 of Class-A IO-Link Master Port (The electrical drawings shown here are simplified for illustration only, the actual implementation drawings may be different)

The two key advantages with this approach are: 1) High amperage output can be used from pin 2 to control valves or solenoids by splitting the port, and 2) IO-Link devices such as valve terminals or configurable I/O hubs that require output power can be connected with standard 4 pole cables without needing additional power cables or connectors.

This does appear very similar to implementation 2 where output power can be provided as well. The key difference is that since the output power comes from a different power line, it is not shared with the device power — as you know, amperage reduces when you have parallel circuits, so implementation 2 is subject to that principle whereas implementation #3 is not.

Another benefit with this approach is that a safety relay can be placed on the power going to pin 2 because the output power for the entire module is separate. That means in case of E-stop situations, the output power can be shut off without harming the device power. This eliminates the need for elaborated controls planning as the device state is maintained throughout the operation. After recovering from an E-stop, the valves and all other outputs go back to their original state. This significantly simplifies your controls architecture, offers standardized approach to cabling and provides unified interface for all devices.

To learn more about Balluff’s implementation of IO-Link masters please visit www.balluff.com.

What Exactly is Safety Over IO-Link?

Users of IO-Link have long been in search of a solution for implementing the demands for functional safety using IO-Link. As a first step, the only possibility was to turn the actuators off using a separate power supply (Port class “B”, Pins 2, 5), which powers down the entire module. Today there is a better answer: Safety hub with IO-Link!

Automation Pyramid.png

This integrated safety concept is the logical continuation of the IO-Link philosophy. It is the only globally available technology to build on the proven IO-Link standards and profisafe. This means it uses the essential IO-Link benefits such as simple data transport and information exchange, high flexibility and universal applicability for safety signals as well. Safety over IO-Link combines automation and safety and represents efficient safety concepts in one system. Best of all, the functionality of the overall system remains unchanged. Safety is provided nearly as an add-on.

In the center of this safety concept is the new safety hub, which is connected to an available port on an IO-Link master. The safety components are connected to it using M12 standard cable. The safety profisafe signals are then tunneled to the controller through an IO-Link master. This has the advantage of allowing existing infrastructure to still be used without any changes. Parameters are configured centrally through the user interface of the controller.

Safety Hub

The safety hub has four 2-channel safe inputs for collecting safety signals, two safe outputs for turning off safety actuators, and two multi-channel ports for connecting things like safety interlocks which require both input and output signals to be processed simultaneously. The system is TÜV- and PNO-certified and can be used up to PLe/SIL 3. Safety components from all manufacturers can be connected to the safe I/O module.

Like IO-Link in general, Safety over IO-Link is characterized by simple system construction, time-and cost-saving wiring using M12 connectors, reduction in control cabinet volume and leaner system concepts. Virtually any network topology can be simply scaled with Safety over IO-Link, whereby the relative share of automation and safety can be varied as desired. Safety over IO-Link also means unlimited flexibility. Thanks to varying port configuration and simple configuration systems, it can be changed even at the last minute. All of this helps reduce costs. Additional savings come from the simple duplication of (PLC-) projects, prewiring of machine segments and short downtimes made possible by ease of component replacement.

Capture

To learn more about Safety over IO-Link, visit www.balluff.com.

 

Flexibility Through Automated Format Changes on Packaging Machines

Digitalization does not stop at the packaging industry. There is a clear trend toward more individual packaging and special formats. What does this mean for packers and packaging machine manufacturers? The variants increase for every single packer, and this leads to a decreased batch size. The packer needs highly flexible machines, which he can easily adjust to the different formats and special variants. The machine manufacturer, in turn, must make these flexible machines available. What does this format change look like? Which technologies can support the packer optimally?

There are two different format adjustment tasks to perform. One is the adjustment of guide rails, side belts or link chains so that they can be adapted to the new format. The other is the changing of parts when a new format is to be produced.

Both tasks have different demands concerning automation technology and therefore there are different solutions available.

Format adjustment

Format adjustment is the adjustment of guide rails, side belts or link chains. In order to carry out this adjustment quickly, safely and error-free, precise position information is required. This recorded position information can then be used to support manual adjustment on the display unit or it can be transferred to the PLC for fully automatic adjustment. One possible solution is to use different position measuring systems. Various standardized interfaces are available as transmission formats, including IO-Link.

Fast format changes in secondary packaging.png
Fast format changes in secondary packaging

IO-Link has ideal features that are predestined for format adjustment: sufficient speed, full access to all parameters, automatic configuration, and absolute transmission of measured values. This eliminates the need for time-consuming reference runs. Since the machine control remains permanently traceable, the effort for error-prone written paper documentation is also saved.

One example for a non-contact absolute position measuring system

BML SL1, IO-Link

A magnetic encoded position measuring system is ideally suited for position detection during format adjustment. It is insensitive to dust, dirt and moisture, offers high accuracy and a measuring length of up to 8,190 mm. Therefore, the position determination and the speed control during the change of guide rails, sidebands or link chains are no problem.

For more information read our previous blog post “Boost Size-Change Efficiency with IO-Link Magnetic Encoders and Visualization”.

Changeable part detection

When changing to a different format size, it is often necessary to not only adjust guide rails but to also replace changeable parts. Machines are becoming more and more flexible, which means that the number of changeable parts per machine is growing.  It is becoming increasingly difficult for the machine operator to find the right part and even more difficult to find the correct mounting position. This conceals some avoidable sources of error. If the replacement part is installed incorrectly, it can cause machine damage, which can lead to downtime.

Therefore, a fast recognition of changeable parts is all about reliably detecting the changeable part at the correct position in the machine. It is also important to make it as easy as possible for the operator to detect possible faults before they happen via a visualization system.

One way of identifying exchangeable parts is industrial identification with RFID.

The right part at the right position

When changing a machine over to a new format you can use RFID data carriers or barcodes to ensure that the correct new parts are being used. Vision sensors also detect whether the part was installed correctly or incorrectly. These solutions help you prevent errors and machine damage, which in turn increases throughput and reduces production costs.

Implement predictive maintenance

With RFID data carriers, the operating times of each change part can be documented directly on the part itself. If a part needs to be cleaned, replaced or reworked, a notification or alarm is issued in the machine controller before fault conditions can arise. RFID data carriers also allow regular cleaning cycles to be logged.

Automate machine settings

Since you can store the individual setting parameters for the change part on the data carrier, the part itself also provides the information to the machine controller. Thus, the change part can trigger a format change in the PLC and change the production process. This is an important step toward intelligent production in the Industry 4.0 concept.

Simple visualization enables expert free operation

With an LED signal lamp, the operator can recognize the operating status of the machine quickly, easily and at a glance. Among other things, it serves to monitor the operating windows and signals whether all settings have been made correctly. The segments of the signal lamp can be configured so that one machine lamp meets a wide range of requirements.

Summary

Format adjustment involves changing guide rails, sidebands or link chains due to a new format. This can be semi-automated or fully automated on the machines. It requires displacement measuring systems whose sensors provide feedback on the respective position.

If format parts on the machine have to be replaced, it must be ensured that the correct changeable part is installed at the correct position in the machine. Industrial identification systems such as RFID are suitable for this purpose. Each changeable part is equipped with a tag and, with the help of the read/write heads, it recognizes whether the correct changeable part is installed in the correct place.

Both automation options offer the following advantages:

  • Short set-up times and increased system productivity
  • Efficient error prevention
  • Increased machine flexibility
  • Avoidance of machine damage due to wrong parts when starting up the machine
  • Simple visualization for the operator

To learn more about format change visit www.balluff.com.

A Smarter SmartLight

Just when you thought the SmartLight was the most flexible Tower Indicator light ever, it gets even more flexible with the addition of a new mode. This new mode is appropriately named “Flexible Mode”. The new Flexible mode enables two new applications: User defined segments and Point-of-use indication.

User Defined Segments

For traditional tower light applications, it’s now Figure 1possible to define the segments as you see fit. It works by taking control of every LED element. Each SmartLight segment is comprised of four LED elements that can be controlled anyway you want (see Figure 1).  For example, with the 3-segment SmartLight, you actually have 12 LED elements that you can organize any way you want. In Figure 2, we only use three LED elements per SmartLight segment, making it a four segment SmartLight. By using two LED elements we create six segments. Figure 3 is even more interesting, in this example we can see the size of the segments are sized by the intended users. Forklift Drivers need a larger light due to the distance and the fact that they are moving. Operators are closer than the forklift drivers, so their segment can be smaller, and maintenance can use the smallest segments because they are closest to the SmartLight when working on the machine.

Point of Use Indication

In these types of applications, the SmartLight is usedSocket Tray App in close proximity, usually within the work envelope of the operators. In the example shown, the SmartLight is used in a socket tray application. The SmartLight indicates to the operator which socket is required for a specific task. Inductive proximity sensors connected to an IO-Link Hub verify the correct socket was pulled. The photo is showing an All-Call (all lights lit). Here you can see the unique LED element grouping only available with the new Flexible mode. Other applications for operator guidance are essentially endless. There are no technical limitations to your creativity.

The Flexible mode is available in all SmartLights with firmware version 3.0 or greater. So go have some fun!

Learn more about the SmartLight at www.balluff.com.

Not all IO-Link Masters are Born Equal!

IO-Link as a standard for device level communication has been around for over a decade. It has started gaining huge momentum in the Americas with 60-70% growth in IO-Link integration in 2017 alone (awaiting official numbers from the IO-Link consortium). Due to this huge market demand for IO-Link, there has been an insurgence of IO-Link masters with features and functionality that is dazzling machine builders and end users alike.

IO-Link Consortium Data (global)

While IO-Link as a communication platform is a standard (IEC 61131-9), the added features and functions leave some machine builders confused on how to reap benefits of these different masters that are around. Some machine builders have a thought process of “Hey, vendor A is selling an IO-Link master and vendor B is also selling an IO-Link master – they are both IO-Link so, why should I pay more?” These machine builders are choosing the lower cost options without realizing what they are missing out on – and sometimes getting disgruntled about the technology itself. On the other hand, some machine builders are spending too much time in measuring and testing a variety of masters – wasting precious time and materials to identify what fits best for their solution. With this blog post and my next, I am hoping to add some clarity on how to detect differences quickly amongst the masters and make a decision that is best suitable for the applications at hand.

IO-Link started out as a standard of communications for smart sensors with a focus to eliminate variety of different interfaces on the plant floor- but since its inception it has manifested itself to be much more than simple sensor integration. It has also gained significance as a backbone for enabling Industry 4.0 or IIoT.  So, let’s review different types of IO-Link masters.

The very first thing machine builders have to do is determine whether the IO-Link master should be IP20 (in cabinet) implementation or IP65-67-69 rated (machine mounted) implementation.

blog

The machine mounted version makes sense as it is suitable for most industrial environments. The IP20 version may be desirable if the machine is operating in extreme environments or experiences continuous changes in temperature, humidity and other factors.

With machine mount masters:

  • It is easier to debug the system with onboard diagnostics availability
  • Eliminates wiring and terminates hassle and saves time and money during the machine building process.

If the IP20 master is your choice, then there isn’t a major difference between vendor A and vendor B IO-Link masters. The difference could appear based on whether the IO-Link master is a part of a larger system or stand-alone module connected to the machine controller through one of the fieldbus or network gateway.  One more thing to note about IP20 masters is they are meant for connecting 3-pin IO-Link devices only. If you want to use architectural benefits of having added Vaux (separate output power) then using IP20 masters becomes complicated and quickly becomes expensive.

If the initial features of machine mounted masters are appealing to you, then there are a few more decisions to be made. The machine mounted IO-Link masters (for simplicity let’s call them IP67 Masters) range from “sensor only” integration capable masters to the ones that have the ability to become a backbone for flexible modular controls architecture. There are primarily three different types of masters as shown below in the chart and they differ based on the power routing capabilities and power handling capabilities.

blog2

In my previous blog entry, “Demystifying Class A and Class B Type IO-Link Ports” I discussed the differences between Class A (Type A) and Class B (Type B) ports and the implications of each type.

We will go over more technical details in my next blog (part 2) to see how power routing and current capabilities make a difference between sensor only applications and a total architecture solution.

To learn more about IO-Link masters, visit www.balluff.com.

Smart IO-Link Sensors for Smart Factories

Digitizing the production world in the age of Industry 4.0 increases the need for information between the various levels of the automation pyramid from the sensor/actuator level up to the enterprise management level. Sensors are the eyes and ears of automation technology, without which there would be no data for such a cross-level flow of information. They are at the scene of the action in the system and provide valuable information as the basis for implementing modern production processes. This in turn allows smart maintenance or repair concepts to be realized, preventing production scrap and increasing system uptime.

This digitizing begins with the sensor itself. Digitizing requires intelligent sensors to enrich equipment models with real data and to gain clarity over equipment and production status. For this, the “eyes and ears” of automation provide additional information beyond their primary function. In addition to data for service life, load level and damage detection environmental information such as temperature, contamination or quality of the alignment with the target object is required.

One Sensor – Multiple Functions

This photoelectric sensor offers these benefits. Along with the switching signal, it also uses IO-Link to provide valuable information about the sensor status or the current ambient conditions. This versatile sensor uses red light and lets you choose from among four sensor modes: background suppression, energetic diffuse, retroreflective or through-beam sensor. These four sensing principles are the most common in use all over the world in photoelectric sensors and have proven themselves in countless industrial applications. In production this gives you additional flexibility, since the sensor principles can be changed at any time, even on-the-fly. Very different objects can always be reliably detected in changing operating conditions. Inventory is also simplified. Instead of four different devices, only one needs to be stocked. Sensor replacement is easy and uncomplicated, since the parameter sets can be updated and loaded via IO-Link at any time. Intelligent sensors are ideal for use with IO-Link and uses data retention to eliminate cumbersome manual setting. All the sensor functions can be configured over IO-Link, so that a remote teach-in can be initiated by the controller.

BOS21M_Infographic_EN_122217

Diagnostics – Smart and Effective

New diagnostics functions also represent a key feature of an intelligent sensor. The additional sensor data generated here lets you realize intelligent maintenance concepts to significantly improve system uptime. An operating hours counter is often built in as an important aid for predictive maintenance.

The light emission values are extremely helpful in many applications, for example, when the ambient conditions result in increased sensor contamination. These values are made available over IO-Link as raw data to be used for trend analyses. A good example of this is the production of automobile tires. If the transport line of freshly vulcanized tires suddenly stops due to a dirty sensor, the tires will bump into each other, resulting in expensive scrap as the still-soft tires are deformed. This also results in a production downtime until the transport line has been cleared, and in the worst case the promised delivery quantities will not be met. Smart sensors, which provide corresponding diagnostic possibilities, quickly pay for themselves in such cases. The light remission values let the plant operator know the degree of sensor contamination so he can initiate a cleaning measure before it comes to a costly production stop.

In the same way, the light remission value BOS21M_ADCAP_Produktbild.png allows you to continuously monitor the quality of the sensor signal. Sooner or later equipment will be subject to vibration or other external influences which result in gradual mechanical misalignment. Over time, the signal quality is degraded as a result and with it the reliability and precision of the object detection. Until now there was no way to recognize this creeping degradation or to evaluate it. Sensors with a preset threshold do let you know when the received amount of light is insufficient, but they are not able to derive a trend from the raw data and perform a quantitative and qualitative evaluation of the detection certainty.

When it comes to operating security, intelligent sensors offer even more. Photoelectric sensors have the possibility to directly monitor the output of the emitter LED. This allows critical operating conditions caused by aging of the LED to be recognized and responded to early. In a similar way, the sensors interior temperature and the supply voltage are monitored as well. Both parameters give you solid information about the load condition of the sensor and with it the failure risk.

Flexible and Clever

Increasing automation is resulting in more and more sensors and devices in plant systems. Along with this, the quantity of transported data that has to be managed by fieldbus nodes and controllers is rising as well. Here intelligent sensors offer great potential for relieving the host controller while at the same time reducing data traffic on the fieldbus. Pre-processing the detection signals right in the sensor represents a noticeable improvement.  A freely configurable count function offers several counting and reset options for a wide variety of applications. The count pulses are evaluated directly in the sensor – without having to pass the pulses themselves on to the controller. Instead, the sensor provides status signals, e.g. when one of the previously configured limit values has been reached. This all happens directly in the sensor, and ensures fast-running processes regardless of the IO-Link data transmission speed.

BOS21M_ADCAP_Anwendungsbeispiel.jpg

Industry 4.0 Benefits

In the age of Industry 4.0 and IoT, the significance of intelligent sensors is increasing. There is a high demand from end users for these sensors since these functions enable them to use their equipment and machines with far greater flexibility than ever before. At the same time they are also the ones who have the greatest advantage when it comes to preventing downtimes and production scrap. Intelligent sensors make it possible to implement intelligent production systems, and the data which they provide enables intelligent control of these systems. In interaction with all intelligent components this enables more efficient utilization of all the machines in a plant and ensures better use of the existing resources. With the increasing spread of Industry 4.0 and IoT solutions, the demand for intelligent sensors as data providers will also continue to grow. In the future, intelligent sensors will be a permanent and necessary component of modern and self-regulating systems, and will therefore have a firm place in every sensor portfolio.

To learn more about these smart sensors, visit www.balluff.com.