IO-Link

Imagine the Perfect Photoelectric Sensor

Guest contributor: Jack Moermond, Balluff

Photoelectric sensors have been around for a long time and have made huge advancements in technology since the 1970’s.  We have gone from incandescent bulbs to modulated LED’s in red light, infrared and laser outputs.  Today we have multiple sensing modes like through-beam, diffuse, background suppression, retroreflective, luminescence, distance measuring and the list goes on and on.  The outputs of the sensors have made leaps from relays to PNP, NPN, PNP/NPN, analog, push/pull, triac, to having timers and counters and now they can communicate on networks.

The ability of the sensor to communicate on a network such as IO-Link is now enabling sensors to be smarter and provide more and more information.  The information provided can tell us the health of the sensor, for example, whether it needs re-alignment to provide us better diagnostics information to make troubleshooting faster thus reducing downtimes.  In addition, we can now distribute I/O over longer distances and configure just the right amount of IO in the required space on the machine reducing installation time.

IO-Link networks enable quick error free replacement of sensors that have failed or have been damaged.  If a sensor fails, the network has the ability to download the operating parameters to the sensor without the need of a programming device.

With all of these advancements in sensor technology why do we still have different sensors for each sensing mode?  Why can’t we have one sensor with one part number that would be completely configurable?

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Just think of the possibilities of a single part number that could be configured for any of the basic sensing modes of through-beam, retroreflective, background suppression and diffuse. To be able to go from 30 or more part numbers to one part would save OEM’s end users a tremendous amount of money in spares. To be able to change the sensing mode on the fly and download the required parameters for a changing process or format change.  Even the ability to teach the sensing switch points on the fly, change the hysteresis, have variable counter and time delays.  Just imagine the ability to get more advanced diagnostics like stress level (I would like that myself), lifetime, operating hours, LED power and so much more.

Obviously we could not have one sensor part number with all of the different light sources but to have a sensor with a light source that could be completely configurable would be phenomenal.  Just think of the applications.  Just think outside the box.  Just imagine the possibilities.  Let us know what your thoughts are.

To learn more about photoelectric sensors, visit www.balluff.com.

cropped-cmafh-logo-with-tagline-caps.pngCMA/Flodyne/Hydradyne is an authorized  Balluff distributor in Illinois, Wisconsin, Iowa and Northern Indiana.

In addition to distribution, we design and fabricate complete engineered systems, including hydraulic power units, electrical control panels, pneumatic panels & aluminum framing. Our advanced components and system solutions are found in a wide variety of industrial applications such as wind energy, solar energy, process control and more.

Demystifying Class A and Class B Type IO-Link Ports

Since the inception of the Class (or Type) A and Class (or Type) B ports in the IO-Link specifications, there have been several new IO-Link devices and IO-Link masters introduced to the market. This has caused a lot of confusion about when and where to use Class A and Class B IO-Link masters and devices.

Before getting into the details of Class A vs. Class B, I would like to address one question that I get asked quite often: are Class B master ports safety-rated? The answer is no. Just like any other network I/O modules (with the exception of the Safety I/O modules), any type of IO-Link master (whether it is Class A, Class B or mixed) is not safety rated. If the block is safety-rated, I am certain that the manufacturers of these blocks will kindly let you know. So, we just busted the first myth about Class B ports. Side note: the IO-Link Consortium just released a specification for IO-Link Safety. At the time of this posting (Oct. 2017), there are no IO-Link masters on the market that are safety rated, even when the IO-Link master ports exist alongside Safety I/O parts on the same block.

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For IO-Link communication, only pins 1, 3 and 4 have significance. The implementations of pin 2 and 5 is where Class A and Class B ports differ and with that, the advantages and disadvantages of the uses for these ports.

Clearly, with the wiring diagrams above, a Class A port offers more flexibility in terms of additional I/O count and in some cases high-amperage outputs to drive high-current devices such as valves.  We will discuss the detailed power routing and application flexibility of Class A ports in a later blog.

With Class B ports, Pin 2 and Pin 5 are tied to a separate power source and cannot really be used as I/O.  Pin 5, the ground for output power, is separated from pin 3, the ground for device power. Actuation devices, such as valve banks, that are now offered on IO-Link could utilize separate output power that can be turned off through safety relays. Technically, this separation of power is possible with Class A ports as well, but it is inherent with Class B ports.

A word of caution when implementing I/O architectures with Class B masters: since the commons for device power and output power are isolated at the master, the power fed to this device should be isolated at the source as well to keep the isolation intact. That means, the power supplies feeding the power to these devices should be isolated.

Another question that I get asked frequently reveals another myth about Class B master ports: do Class B master ports offer any extra power than Class A ports? Again the answer is no. Class B does not mean extra power or the ability to provide more power. It simply means output power with isolated commons. What leads to that thinking is that on several IO-Link masters in the market, the outputs available on pin 2 of Type A ports have lower amperage ratings, because in most cases the output power is shared or drawn from the same source that feeds device power.  There will be more discussion about this in my next blog!

A third interesting question is, can you plug Class A IO-Link devices into Class B master ports? In most cases there is no problem doing this as a true IO-Link Class A device is only a 3 pin device using pins 1,3, and 4 shown above. So as long as pin 2 of the device does not exist or is not being used for any purpose, it is possible to use Class A devices with Class B ports. Caution: several manufacturers make sensors that can be used in IO-Link mode as well as analog or digital mode and the implementation may have more than 3 pins. In these circumstances, you will need to use a 3-pole cable to keep the device unharmed or the pin 2 of the type B port that always has +24V going through may damage or disrupt the sensor.

Meanwhile, I hope this blog helped provide some clarity on Class A and Class B ports.

cropped-cmafh-logo-with-tagline-caps.pngCMA/Flodyne/Hydradyne is an authorized  Balluff distributor in Illinois, Wisconsin, Iowa and Northern Indiana.

In addition to distribution, we design and fabricate complete engineered systems, including hydraulic power units, electrical control panels, pneumatic panels & aluminum framing. Our advanced components and system solutions are found in a wide variety of industrial applications such as wind energy, solar energy, process control and more.

5 Ways Flexible Manufacturing has Never Been Easier

Guest Contributor: Tom Rosenberg, Balluff

Flexible manufacturing has never been easier or more cost effective to implement, even down to lot-size-one, now that IO-Link has become an accepted standard. Fixed control and buried information is no longer acceptable. Driven by the needs of IIoT and Industry 4.0, IO-Link provides the additional data that unlocks the flexibility in modern automation equipment, and it’s here now!  As evidence, here are the top five examples of IO-Link enabled flexibility:

#5. Quick Change Tooling: The technology of inductive coupling connects standard IO-Link devices through an airgap. Change parts and End of Arm (EOA) tooling can quickly and reliably be changed and verified while maintaining connection with sensors and pneumatic valves. This is really cool technology…power through the air!

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#4. On-the-fly Sensors Programming: Many sensor applications require new settings when the target changes, and the targets seem to always change. IO-Link enables this at minimal cost and very little time investment. It’s just built in.

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#3. Flexible Indicator Lights: Detailed communication with the operators no long requires a traditional HMI. In our flexible world, information such as variable process data, timing indication, machine status, run states and change over verification can be displayed at the point of use. This represents endless creativity possibilities.

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#2. Low cost RFID: Radio Frequency Identification (RFID) has been around for a while. But with the cost point of IO-Link, the applications have been rapidly climbing. From traditional manufacturing pallets to change-part tracking, the ease and cost effectiveness of RFID is at a record level. If you have ever thought about RFID, now is the time.

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#1. Move Away from Discrete to Continuously Variable Sensors: Moving from discrete, on-off sensors to continuously variable sensors (like analog but better) opens up tremendous flexibility. This eliminates multiple discrete sensors or re-positioning of sensors. One sensor can handle multiple types and sizes of products with no cost penalty. IO-Link makes this more economical than traditional analog with much more information available. This could be the best technology shift since the move to Ethernet based I/O networks.

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So #1 was the move to Continuously Variable sensors using IO-Link. But the term, “Continuously Variable” doesn’t just roll off the tongue. We have discrete and analog sensors, but what should we call these sensors? Let me know your thoughts!

To learn more about RFID and IO-Link technology, visit www.balluff.com.

cropped-cmafh-logo-with-tagline-caps.pngCMA/Flodyne/Hydradyne is an authorized  Balluff distributor in Illinois, Wisconsin, Iowa and Northern Indiana.

In addition to distribution, we design and fabricate complete engineered systems, including hydraulic power units, electrical control panels, pneumatic panels & aluminum framing. Our advanced components and system solutions are found in a wide variety of industrial applications such as wind energy, solar energy, process control and more.

How do I make my analog sensor less complex?

Guest contributor: Shishir Rege, Balluff

So, you have a (or many) analog sensor in your application or system and they could be 4-20mA signal or 0-10V or even -10- +10V signal strength. You probably know that installing these specialty sensors takes some effort. You need shielded cables for signal transmission, the sensor probably has some digital interface for set-point settings or configuration. In all, there are probably 6-8 at minimum terminations for this single sensor. Furthermore, these expensive cables need to be routed properly to ensure minimal electromagnetic interference (EMI) on the wire. To make matter more complex, when its time to diagnose problem with the sensor, it is always on the back of your mind that may be the cable is catching some interference and giving improper readings or errors.

shieldedCablesOn the other hand, the cost side also is little tricky. You have the state of the art sensor that requires expensive shielded cable and the expensive analog input card (which generally has 4 channels- even if you use single channel), plus some digital I/O to get this single sensor to communicate to your PLC/PAC or controller. You are absolutely right, that is why people are demanding to have this sensor directly on their network so that it eliminates all the expensive cables and cards and talks directly to the controller on express way– so to speak.

Recently, there has been an explosion of industrial communication networks and fieldbuses. To name a few: EtherNet/IP, DeviceNet, PROFINET, PROFIBUS, CC-Link, CC-Link IE, Powerlink, Sercos, and the list goes on. As a machine builder, you want to be open to any network of customer’s choice. So, if that is the case, having network node on the sensor itself would make that sensor more bulky and expensive than before — but not only that, now the manufacturers have to develop sensor connectivity to ALL the networks and maintain separate inventory of each type. As a machine builder, it does put lot more stress on you as well to maintain different Bills of Materials (BOMs) for different projects – most likely – different sourcing channels and so on.

NetworksSo far what we discussed are two extremes; the way of the past with shielded cables and analog cards, and a wishful future where all devices are on the network. There is a middle ground that bridges yesterday’s method and the wishful future without adding any burden on manufacturers of the sensors or even the machine builders. The solution is IO-Link. IO-Link is the first standard (IEC 61131-9) sensor actuator communication technology. There are over 100+ members in the consortium that produce wide variety of sensors that can communicate over IO-Link.

If a sensor has IO-Link communication, denoted by  io-linklogo, then you can connect a standard M12 prox cable — let me stress– UNSHIELDED, to connect the sensor to the IO-Link port on the IO-Link master device. That’s it! No need to terminate connections, or buy expensive hardware. The IO-Link master device typically has 4, 8 or 16 ports to connect various IO-Link devices including I/O hubs, RFID, Valve connectors and more. (see picture below)

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All signal communication and configuration now occurs on standard 3 conductor cable that you are currently using for your discrete sensors. The IO-Link master in turn acts as a gateway to the network. So, the IO-Link master sits on the network or fieldbus and collects all the sensors or discrete I/O information from devices and sends it to the controller or the PLC of the customer choice.

When your customer demands a different network or the fieldbus, the only thing that changes in your question is the master that talks to a different protocol.

In my next blog we will discuss how you can eliminate shielded cables and expensive analog cards for your existing analog sensor. Let me give you a hint– again the solution is with IO-Link.

cropped-cmafh-logo-with-tagline-caps1.pngCMA/Flodyne/Hydradyne is an authorized  Balluff distributor in Illinois, Wisconsin, Iowa and Northern Indiana.

In addition to distribution, we design and fabricate complete engineered systems, including hydraulic power units, electrical control panels, pneumatic panels & aluminum framing. Our advanced components and system solutions are found in a wide variety of industrial applications such as wind energy, solar energy, process control and more.

Solving Analog Integration Conundrum

Guest contributor: Shishir Rege, Balluff

These days, there are several options to solve the integration problems with analog sensors such as measurement or temperature sensors. This blog explains the several options for analog integration and the “expected” benefits.

Before we describe the options, let’s get a few things cleared up.  First, most controllers out there today do not understand analog at all: whenever a controller needs to record an analog value, an analog-to-digital converter is required.  On the other end of the equation is the actual sensor measuring the physical property, such as distance, temperature, pressure, inclination, etc.  This sensor, a transducer, converts the physical property into an analog signal.  These days with the advanced technologies and with the cost of microprocessors going down, it is hard to find a pure analog device.  This is because the piezo-electronics inside the sensor measures the true analog signal, but it is converted to a digital signal so that the microprocessor can synthesize it and convert it back to an analog signal.  You can read more about this in a previous blog of mine “How Do I Make My Analog Sensor Less Complex?

Now let’s review the options available:

  1. The classical approach: an analog to digital converter card is installed inside the control cabinet next to the controller or a PLC. This card offers 2, 4, or even 8 channels of conversion from analog to digital so that the controller can process this information. The analog data can be a current measurement such as 0-20mA or 4-20mA, voltage measurement such as 0-10V, +5- -5V etc., or a temperature measurement such as PT100, PT1000, Type J, Type K and so on.  Prior to networks or IO-Link, this was the only option available, so people did not realize the down-side of this implementation.  The three major downsides are as follows:
  • Long sensor cable runs are required from the sensor all the way to the cabinet, and this required careful termination to ensure proper grounding and shielding.
  • There are no diagnostics available with this approach: it is always a brute-force method to determine whether the cable or the actual transducer/sensor has the issue. This causes longer down-times to troubleshoot problems and leads to a higher cost to maintain the architecture.
  • Every time a sensor needs to be replaced, the right tools have to be found (programming tools or a teaching sequence manual) to calibrate the new sensor before replacement. Again, this just added to the cost of downtime.
  1. The network approach — As networks or fieldbuses gained popularity, the network-based analog modules emerged. The long cable runs became short double-ended pre-wired connectors, significantly reducing the wiring cost. But this solution added the cost of network node and an additional power drop.  This approach did not solve the diagnostic problems (b) or the replacement problem above (c ). The cost of the network analog module was comparable to the analog card, so there was effectively no savings for end users in that area.  As the number of power drops increase, in most cases, the power supply becomes bigger or more power supplies are required for the application.
  2. The IO-Link sensor approach is a great approach to completely eliminate the analog hassle altogether. As I mentioned earlier, since the sensor already has a microprocessor that converts the signal to digital form for synthesis and signal stabilization, why not use that same digital data over a smarter communication to completely get rid of analog? In a nutshell, the data coming out of the sensor is no longer an analog value; instead it is a digital value of the actual result. So, now the controller can directly get the data in engineering units such as psi, bar, Celsius, Fahrenheit, meters, millimeters, and so on. NO MORE SCALING of data in the controller is necessary, there are no more worries of resolution, and best of all enhanced diagnostics are available with the sensor now. So, the sensor can alert the controller through IO-Link event data if it requires maintenance or if it is going out of commission soon.  With this approach, the analog conversion card is replaced by the IO-Link gateway module which comes in 4-channels or 8 channels.

Just to recap about the IO-Link sensor:

  1. IO-Link eliminated the analog cable hassle
  2. IO-Link eliminated the resolution and scaling issue
  3. IO-Link added enhanced diagnostics so that the end users can perform predictive maintenance instead of preventative maintenance.
  4. The IO-Link gateway modules offers configuration and parameter server functionality that allows storing the sensor configuration data either at the IO-Link master port or in the controller so that when it is a time to replace the sensor, all that is required is finding the sensor with the same part number and plugging it in the same port — and the job is done! No more calibration required. Of course, don’t forget to turn on this functionality on the IO-Link master port.

Well, this raises two questions:

  1. Where do I find IO-Link capable sensors? The answer is simple: the IO-Link consortium (www.IO-Link.com) has over 120 member companies that develop IO-Link devices. It is very likely that you will find the sensor in the IO-Link version. Want to use your existing sensor?  Balluff offers some innovative solutions that will allow you bring your analog sensor over to IO-Link.
  2. What is a cost adder for this approach? Well, IO-Link does a lot more than just eliminate your analog hassle. To find out more please visit my earlier blog “Is IO-Link only for Simplifying Sensor Integration?

 

cropped-cmafh-logo-with-tagline-caps1.pngCMA/Flodyne/Hydradyne is an authorized  Balluff distributor in Illinois, Wisconsin, Iowa and Northern Indiana.

In addition to distribution, we design and fabricate complete engineered systems, including hydraulic power units, electrical control panels, pneumatic panels & aluminum framing. Our advanced components and system solutions are found in a wide variety of industrial applications such as wind energy, solar energy, process control and more.

Non-Contact Infrared Temperature Sensors with IO-Link – Enabler for Industry 4.0

Guest contributor: Manfred Munzl for Balluff

Automation in Steel-Plants

Modern production requires a very high level of automation. One big benefit of fully automated plants and processes is the reduction of faults and mishaps that may lead to highly expensive downtime. In large steel plants there are hundreds of red hot steel slabs moving around, being processed, milled and manufactured into various products such as wires, coils and bars. Keeping track of these objects is of utmost importance to ensure a smooth and cost efficient production. A blockage or damage of a production line usually leads to an unexpected downtime and it takes hours to be rectified and restart the process.

To meet the challenges of the manufacturing processes in modern steel plants you need to control and monitor automatically material flows. This applies especially the path of the workpieces through the plant (as components of the product to be manufactured) and will be placed also at locations with limited access or hazardous areas within the factory.

Detection of Hot Metal

Standard sensors such as inductive or photoelectric devices cannot be used near red hot objects as they either would be damaged by the heat or would be overloaded with the tremendous infrared radiation emitted by the object. However, there is a sensing principle that uses this infrared radiation to detect the hot object and even gives a clue about its temperature.

Non-contact infrared thermometers meet the requirements and are successfully used in this kind of application. They can be mounted away from the hot object so they are not destroyed by the heat, yet they capture the Infrared emitted as this radiation travels virtually unlimited. Moreover, the wavelength and intensity of the radiation can be evaluated to allow for a pretty accurate temperature reading of the object. Still there are certain parameters to be set or taught to make the device work correctly. As many of these infrared thermometers are placed in hazardous or inaccessible places, a parametrization or adjustment directly at the device is often difficult or even impossible. Therefore, an intelligent interface is required both to monitor and read out data generated by the sensor and – even more important – to download parameters and other data to the sensor.

Technical basics of Infrared Hot-Metal-Detectors

Traditional photoelectric sensors generate a signal and receive in most cases a reflection of this signal. Contrary to this, an infrared sensor does not emit any signal. The physical basics of an infrared sensor is to detect infrared radiation which is emitted by any object.
Each body, with a temperature above absolute zero (-273.15°C or −459.67 °F) emits an
electromagnetic radiation from its surface, which is proportional to its intrinsic
temperature. This radiation is called temperature or heat radiation.

By use of different technologies, such as photodiodes or thermopiles, this radiation can be detected and measured over a long distance.

Key Advantages of Infrared Thermometry

This non-contact, optical-based measuring method offers various advantages over thermometers with direct contact:

  • Reactionless measurement, i.e. the measured object remains unaffected, making it possible to measure the temperature of very small parts
  • Very fast measuring frequence
  • Measurement over long distances is possible, measuring device can be located outside the hazardous area
  • Very hot temperatures can be measured
  • Object detection of very hot parts: pyrometers can be used for object detection of very hot parts where conventional optical sensors are limited by the high infrared radiation
  • Measurement of moving objects is possible
  • No wear at the measuring point
  • Non-hazardous measurement of electrically live parts

IO-Link for smarter sensors

IO-Link as sensor interface has been established for nearly all sensor types in the past 10 years. It is a standardized uniform interface for sensors and actuators irrespective of their complexity. They provide consistent communication between devices and the control system/HMI.  It also allows for a dynamic change of sensor parameters by the controller or the operator on the HMI thus reducing downtimes for product changeovers. If a device needs to be replaced there is automatic parameter reassignment as soon as the new device has been installed and connected. This too reduces manual intervention and prevents incorrect settings. No special device-proprietary software is needed and wiring is easy, using three wire standard cables without any need for shielding.

Therefore, IO-Link is the ideal interface for a non-contact temperature sensor.

All values and data generated within the temperature sensor can be uploaded to the control system and can be used for condition monitoring and preventive maintenance purposes. As steel plants need to know in-process data to maintain a constant high quality of their products, sensors that provide more data than just a binary signal will generate extra benefit for a reliable, smooth production in the Industry 4.0 realm.

To learn more about this technology visit www.balluff.com.

cropped-cmafh-logo-with-tagline-caps.pngCMA/Flodyne/Hydradyne is an authorized  Balluff distributor in Illinois, Wisconsin, Iowa and Northern Indiana.

In addition to distribution, we design and fabricate complete engineered systems, including hydraulic power units, electrical control panels, pneumatic panels & aluminum framing. Our advanced components and system solutions are found in a wide variety of industrial applications such as wind energy, solar energy, process control and more.

How hot is hot? The basics of Infrared Temperature Sensors

Guest Contributor:  Jack Moermond, Balluff

Detecting hot objects in industrial applications can be quite challenging. There are a number of technologies available for these applications depending on the temperatures involved and the accuracy required. In this blog we are going to focus on infrared temperature sensors.

Every object with a temperature above absolute zero (-273.15°C or -459.8°F) emits infrared light in proportion to its temperature. The amount and type of radiation enables the temperature of the object to be determined.

In an infrared temperature sensor a lens focuses the thermal radiation emitted by the object on to an infrared detector. The rays are restricted in the IR temperature sensor by a diaphragm, to create a precise measuring spot on the object. Any false radiation is blocked at the lens by a spectral filter. The infrared detector converts radiation into an electrical signal. This is also proportional to the temperature of the target object and is used for signal processing in a digital processor. This electrical signal is the basis for all functions of the temperature sensor.

There are a number of factors that need to be taken into account when selecting an infrared temperature sensor.

  • What is the temperature range of the application?
    • The temperature range can vary. Balluff’s BTS infrared sensor, for example, has a range of 250°C to 1,250°C or for those Fahrenheit fans 482°F to 2,282° This temperature range covers a majority of heat treating, steel processing, and other industrial applications.
  • What is the size of the object or target?
    • The target must completely fill the light spot or viewing area of the sensor completely to ensure an accurate reading. The resolution of the optics is a relationship to the distance and the diameter of the spot.

  • Is the target moving?
    • One of the major advantages of an infrared temperature sensor is its ability to detect high temperatures of moving objects with fast response times without contact and from safe distances.
  • What type of output is required?
    • Infrared temperature sensors can have both an analog output of 4-20mA to correspond to the temperature and is robust enough to survive industrial applications and longer run lengths. In addition, some sensors also have a programmable digital output for alarms or go no go signals.
    • Smart infrared temperature sensors also have the ability to communicate on networks such as IO-Link. This network enables full parameterization while providing diagnostics and other valuable process information.

Infrared temperature sensors allow you to monitor temperature ranges without contact and with no feedback effect, detect hot objects, and measure temperatures. A variety of setting options and special processing functions enable use in a wide range of applications. The IO-Link interface allows parameterizing of the sensor remotely, e.g. by the host controller.

For more information visit www.balluff.com

cropped-cmafh-logo-with-tagline-caps.pngCMA/Flodyne/Hydradyne is an authorized  Balluff distributor in Illinois, Wisconsin, Iowa and Northern Indiana.

In addition to distribution, we design and fabricate complete engineered systems, including hydraulic power units, electrical control panels, pneumatic panels & aluminum framing. Our advanced components and system solutions are found in a wide variety of industrial applications such as wind energy, solar energy, process control and more.