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

How RFID Can Push Your Automotive Production Into the Fast Lane

The automotive industry is one of the technological trendsetters in the manufacturing industry. In 1913 Henry Ford invented the assembly line and forever changed automotive production. Now a bit more than a century later the automotive industry is again facing one the biggest innovations in its history.

The complexity of different models and the variety of equipment variations are enormous. This individuality comes with great challenges. The workers in the assembly process are confronted with countless, almost identical components. This requires accurate tracking of all items to avoid mistakes. Safety-relevant components are, therefore, often provided with a barcode that has to be scanned manually.

The major advantages of RFID over barcodes in automotive production

Another technology could relieve employees of this routine task and give them the security of having installed the right parts through automatic testing: RFID. These are the big advantages of RFID over barcodes:

  • While the barcode only contains the information about which type of product it is, the RFID tag provides additional information, such as in which vehicle the car seat is to be installed.
  • While the barcodes have to be read out manually one after the other with a handheld scanner, the RFID tags can all be detected simultaneously and without contact via a scanner – even if the parts are already installed.
  • RFID tags can be used to retrieve information in seconds at any time. During the production process, it can already be checked whether all the required components are installed –  provided they are all equipped with an RFID tag. Without RFID, this was only recorded in the final inspection, using visual inspection and paper list.
  • Additionally, nowadays it is indispensable for the automotive industry to make the production parts traceable and thereby assign them a unique identity. RFID has the advantage that without visual contact or even after a repainting of the component, the information can be easily retrieved. The function is not lost with dirt or oil coverage. Furthermore, tags with special encapsulation can retain their function even under high mechanical, thermal or chemical loads.

How does RFID work?

RFID is the identification of objects by electromagnetic waves.  A reader generates a high-frequency electromagnetic field. If a data carrier (also called “tag”) is brought into the vicinity of the reader, the specific structure of the tag ensures a change in the field and thus transmits individual information about itself – contactless.

RFID Tag and Reader
Functional principle of an RFID system

Increase process reliability and profitability with RFID

Several thousand parts are needed to build a car. But only those parts that are safety, environmentally or testing relevant get an RFID tag. For example, the motor cabling would get a tag that can be read out automatically. Without RFID a worker would have to manually enter the label in a database and errors can easily arise. RFID detects the part automatically and you don’t have to look for labels in transport boxes, etc.

With RFID you know exactly where a component is located at any time – from the moment of delivery until the belt run of the car. With this information you can react flexibly to changes in the process, such as delays in certain areas, and can reschedule at short notice. In addition, you can always retrieve the current stock and know whether the right component is mounted on the right vehicle. So it can significantly increase process reliability and efficiency. An RFID solution eliminates several manual steps in the documentation per vehicle, and it brings more transparency to the logistics and production processes. That means the effort is reduced and the profitability increases.

The implementation starts with the suppliers

Ideally, the implementation of RFID starts with the automotive suppliers. They attach the RFID tags to their components what allows them to use the technology within their own logistics and manufacturing facilities. On arrival to the car manufacturer, the parts are driven through an RFID gate that reads out the tags automatically and adds the parts to the inventory. If the car leaves the assembly hall after manufacturing you can screen again by the RFID gate. At the push of a button it can show which parts are under the hood.

Automatic configuration with UHF for your convenience

The processes in the automotive industry are versatile, but a broad selection of innovative RFID products can push your automotive production into the fast lane.

For more information on RFID, visit

Basics of 3-Wire DC Sensor Output Protection

Most sensors offered today by reputable manufacturers include some type of electrical output protection that prevents sensor damage in the event of a wiring fault. There are a variety of protection methods and functions available, so let’s take a quick look at some of the most commonly found types.

Polarity Reversal Protection

This one is fairly straightforward and does just what its name implies. In case of accidentally reversed positive and common power leads, a series diode prevents any reverse flow of current that could damage the internal sensor electronics.

Miswiring Protection

This takes polarity reversal protection to the next logical step. Any of the three sensor wires can be misconnected in any combination and the sensor will not be damaged. For example, output to positive, common to load, and positive to common. Or, output and common to positive, and positive to load … you get the idea. Regardless, the sensor will be protected and will function normally once it is properly connected.

In either case of reversed polarity or other miswiring, although the sensor won’t be damaged, the sensor still represents a system fault and will require troubleshooting. This is why more and more machine builders and plant operators are moving away from hand-terminated sensor cables and toward double-ended quick-disconnect cordsets and distributed modular I/O over IO-Link.

Short-Circuit Protection (SCP)

This protects the output of the sensor from damage if it is connected to a dead short. Left unprotected, the sensor’s output becomes a fuse and “blows”, permanently destroying the sensor.

There are three types of short-circuit protection in use:

  • Thermal
  • Latching solid state
  • Pulsing solid state

Thermal SCP utilizes series device called a thermistor. As current through it rises, its resistance increases, which acts to throttle the current to a safe level. When the short circuit is removed, the sensor requires a cool down period before it can resume normal function. This is a crude form of short-circuit protection; modern 3-wire sensors no longer employ this method but some older types or some from lesser-known manufacturers may still be using it. One potential advantage for thermal SCP is that it has an inherent time delay that allows for a slightly longer, larger inrush current. This may be helpful in starting some high inrush loads like larger relays or incandescent lamps. However, in most cases today there is no need for a sensor to directly pilot loads like this. Most sensors today have a PLC input as a load.

Thermal Short-Circuit Protection

Latching solid state SCP was common in the past but today is less widely used. When the output current exceeds a defined threshold, the output circuit opens, stopping the flow of current. To reset the sensor after the fault, power to the sensor must be cycled (interrupted and re-applied). This can create a nuisance if the fault is intermittent, because someone has to disconnect and reconnect the sensor to reset it. However, at least the fault condition is captured every time it occurs.

Latching Short-Circuit Protection.JPG

Pulsing solid state SCP is used in most of today’s high-performance sensor designs. The sensor monitors the output for a short circuit and interrupts it the moment the current exceeds the design threshold. Subsequently, the electronics will start to continuously attempt to close the output to see if the fault has been removed. If not, it keeps removing and reapplying power to the output in a “pulsing” manner. If there is an intermittent fault, the sensor will resume normal function when the fault goes away. Sometimes this is called “automatic reset” (as opposed to latching SCP, which is manual reset). Automatic reset can be helpful, or it can be a nuisance. Because the fault isn’t latched, it may be hard to track down which sensor is being shorted if the fault is intermittent. On the plus side, if the fault was one-and-done, the sensor resumes normal function and production continues without further interruption.

Pulsing Short-Circuit Protection

The need to capture short-circuit events is one of the reasons more and more control systems are going with distributed modular I/O blocks using IO-Link. The input port of the block will detect the short circuit and will begin pulsing power to protect the sensor. Although it will automatically reset if the fault is removed, the block will send a fault message to the controller indicating which port was faulted. Note, however, that not all I/O blocks can interrupt a short circuit only at the port level. Many blocks will fault the entire block when only one port is affected. Be sure to ask any potential block supplier how their blocks behave during short-circuit events.

Overload Protection

This circuit monitors the length of time that higher-than-normal (but not short-circuit) load current is flowing. Over time, this can cause overheating of the sensor and subsequent damage. Overload Protection will detect this excessive-current condition and — depending on the type of SCP employed —either reduce current to a safe level (thermal SCP), turn the output off (latching SCP), or pulse the output (pulsing SCP).

Surge Protection

Also sometimes called Overvoltage Protection, this circuit monitors the incoming power supply voltage. When it exceeds the safe threshold, an internal circuit shunts the excessive voltage and clamps the applied voltage to the sensor at a safe level.

Inductive Overvoltage Protection

This circuit prevents sensor output damage from high voltages generated by “back EMF” (Electromotive Force) when an inductive load (like a relay coil) is switched off. Sometimes this is referred to as “inductive kickback”. Since current through an inductor tries to remain constant, the voltage across the inductor rises as the current falls to try to keep it flowing at the same level. The voltage can rise to very high levels, hundreds or thousands of volts, and will appear on the sensor’s output line. (In fact, this generation of high voltage from the collapse of current through an inductor is exactly how automotive spark ignition coils operate.)

So, how does inductive overvoltage protection work? Inside the sensor, a shunt device called a “freewheeling diode” allows the current to continue circulating harmlessly through the inductive load while it decays, preventing the buildup of damaging high voltage.

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.


To learn more about Safety over IO-Link, visit


When and Where to Use Continuous Cylinder Position Sensing

The role of smart cylinders — hydraulic or pneumatic cylinders with integrated position detection capability — has increased as manufacturers constantly strive to improve efficiency through automation. Smart cylinders can use either continuous or discrete position sensing, providing manufacturers with options, but possibly leaving them with questions on which is best for their application.

In this post we will review the benefits of continuous position sensors and list the applications where this is the best fit.

Continuous position sensors provide near real-time position feedback throughout the entire stroke of the cylinder making them the ideal choice for applications at the higher end of the control spectrum. Closed-loop servohydraulic systems can achieve sophisticated, dynamic control of motion across the entire cylinder stroke.

Continuous position sensors are commonly used when the application calls for closed-loop servo control, where the position, speed, acceleration, and deceleration of the cylinder must be controlled. Closed-loop servohydraulics have been widely used in industrial applications, such as sawmills, steel processing and tire manufacturing, and more recently in cylinders in off-highway equipment.

Magnetostrictive linear position sensors are the most commonly used continuous position sensors in hydraulic cylinders. These sensors are installed into the back end of the cylinder. The sensor detects the position of a magnet attached to the piston and provides a continuous, absolute position signal.

Magnetostrictive linear position sensor installed in hydraulic cylinder

The sensor is rated to withstand the full pressure of the hydraulic system. Magnetostrictive technology offers the advantage of being completely non-contact, meaning it requires no mechanical contact between the sensor and the moving cylinder and is not subject to wear and performance degradation. In addition, numerous electrical interface options are available, from simple analog (0 to 10V or 4-20mA) to high-performance industrial fieldbus interfaces that offer advanced functionality.

Continuous position sensors can also be used in pneumatic cylinders. While closed-loop servo control with pneumatics is not as common as it is with hydraulics, there are situations where pneumatic cylinders require continuous position sensing capability. For example, low-pressure pneumatic cylinders are sometimes used as measurement probes, or touch probes, where the cylinder rod is extended until it touches a part to be measured or gaged. In these situations, it is beneficial to be able to get continuous position feedback, especially when there is variability in the measured part.

To learn more about cylinder position sensing, visit

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.


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

Distance Measurement with Inductive Sensors

When we think about inductive sensors we automatically refer to discrete output offerings that detect the presence of ferrous materials. This can be a production part or an integrated part of the machine to simply determine position. Inductive sensors have been around for a long time, and there will always be a need for them in automated assembly lines, weld cells and stamping presses.

We often come across applications where we need an analog output at short range that needs to detect ferrous materials. This is an ideal application for an analog inductive proximity sensor that can offer an analog voltage or analog current output. This can reliably measure or error proof different product features such as varying shapes and sizes. Analog inductive sensors are pure analog devices that maintain a very good resolution with a high repeat accuracy. Similar to standard inductive sensors, they deal very well with vibration, commonly found in robust applications. Analog inductive proximity sensors are also offered in many form factors from M12-M30 tubular housings, rectangular block style and flat housings. They can also be selected to have flush or non-flush mounting features to accommodate specific operating distances needed in various applications.

Application Examples:



For more specific information on analog inductive sensors visit

Optimized Utilization and Increased Transparency with RFID

Unscheduled downtimes in production due to worn out or unserviced molds in machines can cause high costs and are a well-known problem for a lot of companies. In order to prevent these issues and optimize the use of their injection molds, a Swiss chocolate mold producer installed a predictive maintenance system via industrial RFID technology.

Maintaining oversight during frequent mold changes with RFID

Complex and expensive injection molds are typically used in manufacturing parts. Due to wear and contamination, they require regular cleaning, care and maintenance. The regularity often depends on handwritten records in a molds log-book, post-its or on the experience of the employees. In more modern companies, databases or excel sheets may be used to store this information. Regardless of the method, real-world experience shows that manual recording is often prone to errors. Maintenance and inspection are often only carried out if a mold malfunctions, when it tends to be too late.

Poured chocolate molds endure wear and need regular maintenance

Poured chocolate molds, that are used in continuous operation on the production lines of chocolate manufacturers, are known worldwide for their perfection and durability. In most cases, they are made in comparatively small batch sizes of 1500 to 2000 units. For this reason, the injection molds have a modular structure. The base is a master mold with exchangeable inserts which leads to quick and frequent mold change cycles. Additionally, there are certain things that require increased maintenance, like replacing hoses, lines or connecting components, that involve removing the master mold. This is why it is especially important to keep track of how many times a master mold has been used. A control system via industrial RFID technology can be installed to solve this problem.

Continue reading “Optimized Utilization and Increased Transparency with RFID”

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

Back to the Basics – Object Detection

In the last post about the Basics of Automation, we discussed how humans act as a paradigm for automation. Now, let’s take a closer look at how objects can be detected, collected and positioned with the help of sensors.

Sensors can detect various materials such as metals, non-metals, solids and liquids, all completely without contact. You can use magnetic fields, light and sound to do this. The type of material you are trying to detect will determine the type of sensor technology that you will use.

Object Detection 1

Types of Sensors

  • Inductive sensors for detecting any metallic object at close range
  • Capacitive sensors for detecting the presence of level of almost any material and liquid at close range
  • Photoelectric sensors such as diffuse, retro-reflective or through-beam detect virtually any object over greater distances
  • Ultrasonic sensors for detecting virtually any object over greater distances

Different Sensors for Different Applications

The different types of sensors used will depend on the type of application. For example, you will use different sensors for metal detection, non-metal detection, magnet detection, and level detection.

Detecting Metals

If a workpiece or similar metallic objects Object Detection 2should be detected, then an inductive sensor is the best solution. Inductive sensors easily detect workpiece carriers at close range. If a workpiece is missing it will be reliably detected. Photoelectric sensors detect small objects, for example, steel springs as they are brought in for processing. Thus ensures a correct installation and assists in process continuity. These sensors also stand out with their long ranges.

Detecting Non-Metals

If you are trying to detect non-metal objects, for example, the height of paper stacks, Object Detection 3then capacitive sensors are the right choice. They will ensure that the printing process runs smoothly and they prevent transport backups. If you are checking the presence of photovoltaic cells or similar objects as they are brought in for processing, then photoelectic sensors would be the correct choice for the application.

Detecting Magnets

Object Detection 4

To make sure that blister packs are exactly positioned in boxes or that improperly packaged matches are sorted out, a magnetic field sensor is needed which is integrated into the slot. It detects the opening condition of a gripper, or the position of a pneumatic ejector.


Level Detection

What if you need to detect the level of granulate in containers? Then the solution is to use capacitive sensors. To accomplish this, two sensors are attached in the containers, offset from each other. A signal is generated when the minimum or maximum level is exceeded. This prevents over-filling or the level falling below a set amount. However, if you would like to detect the precise fill height of a tank without contact, then the solution would be to use an ultrasonic sensor.

Stay tuned for future posts that will cover the essentials of automation. To learn more about the Basics of Automation in the meantime, visit