Building Blocks of the Smart Factory Now More Economical, Accessible

A smart factory is one of the essential components in Industry 4.0. Data visibility is a critical component to ultimately achieve real-time production visualization within a smart factory. With the advent of IIoT and big-data technologies, manufacturers are finally gaining the same real-time visibility into their enterprise performance that corporate functions like finance and sales have enjoyed for years.

The ultimate feature-rich smart factory can be defined as a flexible system that self-optimizes its performance over a network and self-adapts to learn and react to new conditions in real-time. This seems like a farfetched goal, but we already have the technology and knowhow from advances developed in different fields of computer science such as machine learning and artificial intelligence. These technologies are already successfully being used in other industries like self-driving cars or cryptocurrencies.

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Fig: Smart factory characteristics (Source: Deloitte University Press)

Until recently, the implementation or even the idea of a smart factory was elusive due to the prohibitive costs of computing and storage. Today, advancements in the fields of machine learning and AI and easy accessibility to cloud solutions for analytics, such as IBM Watson or similar companies, has made getting started in this field relatively easy.

One of the significant contributors in smart factory data visualization has been the growing number of IO-Link sensors in the market. These sensors not only produce the standard sensor data but also provide a wealth of diagnostic data and monitoring while being sold at a similar price point as non-IO-Link sensors. The data produced can be fed into these smart factory systems for condition monitoring and preventive maintenance. As they begin to produce self-monitoring data, they become the lifeblood of the smart factory.

Components

The tools that have been used in the IT industry for decades for visualizing and monitoring server load and performance can be easily integrated into the existing plant floor to get seamless data visibility and dashboards. There are two significant components of this system: Edge gateway and Applications.

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Fig: An IIoT system

Edge Gateway

The edge gateway is the middleware that connects the operation technology and Information technology. It can be a piece of software or hardware and software solutions that act as a universal protocol translator.

As shown in the figure, the edge gateway can be as simple as something that dumps the data in a database or connects to cloud providers for analytics or third-party solutions.

Applications

One of the most popular stacks is Influxdb to store the data, Telegraf as the collector, and Grafana as a frontend dashboard.

These tools are open source and give customers the opportunity to dive into the IIoT and get data visibility without prohibitive costs. These can be easily deployed into a small local PC in the network with minimal investment.

The applications discussed in the post:

Grafana

Telegraf

Influxdb

Node-red Tutorial

Analog Inductive Sensors Enable Easy Double Blank Detection in Stamping

Double sheet detection, also known as double blank detection, is an essential step in stamping quality control processes, as failure to do so can cause costly damage and downtime. Analog inductive sensors can deliver a cost-effective and easy way to add this step to stamping processes.

Most people have experienced on a smaller scale what happens when the office printer accidentally feeds two sheets of paper; the machine jams and the clog must be manually removed. Beyond the annoyance of not getting the printout right away, this typically doesn’t cause any significant issues to the equipment. In the stamping world, two sheets being fed into a machine can severely affect productivity and quality.

When two metal sheets stick together and are fed into a machine together, the additional thickness can damage the stamping dies and other equipment like the robot loaders, which can cause the production line to shut down for repairs. Even if the tool fares better and does not get damaged, the stamped product will likely be defective. In today’s highly competitive and just-in-time market, machine downtime and rejected shipments due to quality can be very costly.

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A simple solution to detect multiple sheets of metal is analog inductive sensing. This kind of sensor offers non-contact sensing with a 0…10V analog output, which can be used to determine when the thickness of the metallic material changes. As the material gets thicker, or as multiple sheets of metal stack on top of one another, the analog output from the sensor varies proportionally. These sensors can be used with ferrous or non-ferrous metals, but the operating range will be reduced for non-ferrous metals. As shown in the graph (Image 1), as the distance with the metallic target changes, the analog output increases from 0 to 10V.

 

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The pictures above, shows the technology in action. With a single sheet of aluminum, the output from the sensor is 2.946V, and for two sheets, the output is 5.67V. The user can establish these values as a reference for when there is more than one sheet of metal being fed into the machine and stop the equipment from attempting to process the material before it is damaged. These sensors can be placed perpendicular or inline with the target material and are offered in various form factors so they can be integrated into a wide range of applications.

 

 

 

IO-Link Parameterization Maximizes Functionality, Reduces Expenses

Parameters are the key to maximizing performance and stretching sensor functionality on machines through IO-Link. They are typically addressed during set up and then often underutilized because they are misunderstood. Even users familiar with IO-Link parameters often don’t know the best method for adjustment in their systems and how to benefit from using them.

Using parameters reduces setup time
During standard installation, users must acquire all manuals for each IO-Link device and then hope that all manufactures provided detailed information for parameter setting. All IO-Link device manufacturers are required to produce an IODD file, which can be accessed through the IODD Finder. This IODD file provides a list of available parameters for an IO-Link device which will save the user time by eliminating the need for manuals. Some IO-Link masters can permanently store IODD files for rapid IO-Link parameterization. This feature brings the parameters into an online webpage and gives drop down menus with all available options along with buttons for reading and writing the parameters.

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Maximize functionality of the device
Setpoints can be changed on the fly during normal operation of the machine which will allow a device to expand to the actual range and resolution of each device. Multiple pieces of information can be extracted through IO-Link parameters that are not typically available in process data. One example being an IO-Link pressure sensor with a thermistor included so that temperature can be recorded in the parameters while sending normal pressure values. This allows the user to understand the health of their devices and gather optimal information for more visibility into their processes.

Allows for backup and recovery
IO-Link parameterization allows the user to read and write ALL parameters of IO-Link Data of the device. For example, a two-set point sensor will typically have a teach button/potentiometer that technically limits adjustment for only two parameters and cannot be backed up. This method leaves devices vulnerable to extended downtime from loss of setpoints as well as adding complex teach functions that are not precise. IO-Link parameterization on the other hand pulls teach buttons/potentiometers into the digital world with precision and repeatability. Some IO-Link master blocks have a parameter server function that backs up device parameters in case a sensor needs to be replaced, ultimately providing predictive maintenance, reduced downtime, and easy recipe changes quickly throughout the process.

Using IO Link parameterization is highly important because it reduces setup time, maximizes the functionality of the IO-Link device, and allows for backup and recovery of the parameters. Implementing parameters results in being more cost effective and decreases frustration during the installation process and required maintenance. These parameter functions are just one of the many benefits of using IO Link.

From Design and Build, to Operation and Maintenance, IO-Link Adds Flexibility

With almost twelve million installed nodes as of 2019, IO-Link is being rapidly adopted in a wide range of industries and applications. It is no wonder since it provides more flexibility in how we build and maintain our machines and delivers more data.

Design
As an IEC standard (IEC 61131-9), IO-Link provides consistency in how our devices are connected and integrated. With an already large and ever growing base of manufacturers providing IO-Link devices, we have an incredible amount of choice when it comes to what vendors we use and what devices we incorporate into our systems, all while having the confidence that all of these devices will work and communicate together. Fieldbus independent and based on a point-to-point connection using standard 3 and 4 wire sensor cables, IO-Link allows designers to replace PLC input cards in the control cabinet with machine-mounted IO-Link masters and input hubs. This technology means we are drastically less limited in how we design our machines.

Build/Commissioning
IO-Link is well known for simplifying and reducing build time of machines. Standardization of connections means that readily available double ended quick disconnect sensor cables can replace individually terminated wires, and analogue devices and devices using RS232 connections can be replaced with IO-Link devices which connect directly to a machine mounted IO-Link master or IO hub. Simplified wiring along with delivered diagnostics leads to greatly simplified network architecture and reduced build/commissioning time, as well as increased trouble shooting ability. This all leads to reduced hardware and labor cost.

When it comes to the software side of things, you might think that all of this additional functionality and flexibility increases the burden on programmers, however through the use of configuration files provided by the device manufacturers for both the IO-Link devices and the PLC, this additional functionality and data is at our fingertips with minimal time and effort. With the large adoption of IO-Link and growing manufacturer base comes great amounts of reference material, videos, example programs, and support, all of which can help to get our systems up and running quickly.

Operation
When it comes to operation IO-Link opens a world of possibilities. Bidirectional communication of not only process data but diagnostics and parameter data delivers real time visibility into the entire system during operation all the way down to the device level. Things like automated or guided changeover become possible, for example if a manufacturer produces two different parts on the same line, after the production of part A, devices can be reparameterized for production of part B with the push of a button.

Maintenance
Maintenance sees massive benefits from IO-Link thanks to reduced unplanned downtime through device diagnostics which allow for predictive maintenance practices. If a device does get damaged or fails at an inconvenient time, the issue can be found much quicker and be replaced. Once the IO-Link master recognizes that the device was replaced with the same hardware ID, it can automatically reparameterize the device.

IO-Link is already making our lives easier and providing manufacturers with more possibilities in their automated systems, and as we push into Industry 4.0 it continues to prove its value.

For more information on IO-Link and Industry 4.0 visit www.Balluff.com

 

Mobile Equipment Manufacturers: Is It Time to Make the Switch to Inductive Position Sensors?

Manufacturers of mobile equipment are tasked with the never-ending pursuit of making their machines more productive while adhering to the latest safety regulations, and all at less cost. To help achieve these goals, machines today use electronic control modules to process inputs and provide outputs that ultimately control the machine functions. Yet with all the changes in recent years, one component left over from that earlier era remains in regular use — the mechanical switch.  Switches offered a variety of levers, rollers, and wands for actuation, and many were sealed for an IP67 rating for outdoor use, but they came with an array of problems, including damaged levers, contact corrosion, arcing concerns, dirt or grain dust ingress, and other environmental hazards. Still, overall they were an acceptable and inexpensive way to receive position feedback for on/off functions.

Today, mechanical switches can still be found on machines used for boom presence, turret location, and other discrete functions. But are they the right product for today’s machines?

The original design parameters may have required the switch to drive the load directly, and therefore a rating of 10A@240V might be a good design choice for the relay/diode logic circuits of the past. But a newly designed machine may be switching mere milliamps through the switch into the control module. Does the legacy switch have the proper contact plating material for the load today? Switches use rare metals such as rhodium, palladium, platinum, gold, and silver in attempts to keep the contact resistance low and to protect those contacts from corrosion. Consequently, as China pursues Nonroad Stage IV standards, these metals, some also used in catalytic converters, have sharply increased in price, leading to substantial cost increases to switch manufacturers and ultimately switch users.

A better approach to position feedback for today’s mobile machines is the inductive position sensor. Inductive sensors offer a sealed, non-contact alternative to mechanical switches. Sensing ferrous and non-ferrous metals without physical contact, they eliminate many of the field problems of the past, and non-metallic substances such as water, dirt, and grain dust, do not affect the operation. These qualities make the sensor very suitable for the harsh conditions found in agricultural and construction environments.

Inductive proximity sensors come in a variety of form factors:

Threaded cylindrical – With zinc-plated brass or stainless-steel housings, the threaded barrel styles are popular for their ease of mounting and gap adjustment.  

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Low profile rectangular – These “flatpack” style sensors are great under seats for operator presence.

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Block designs – The compact, cubed package is ideal for larger sensing ranges.

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Large cylindrical – These large “pancake” style sensors are great for detecting suspension movements and other applications requiring extreme ranges.

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Inductive position sensors are more than just a discrete product used for detecting linkage, operator presence, or turret stops; They can also perform the duties of a speed sensor by counting teeth (or holes) to determine the RPM of a rotating shaft. Other models offer analog outputs to provide a continuous feedback signal based on the linear location of a metal linkage or lever. Safety rated outputs, high temperatures, and hazardous area options are some of the many product variants available with this electromagnetic technology.
So, perhaps it’s time to review that legacy switch and consider an inductive sensor?
To learn how an inductive position sensor performs its magic, please take a look at an earlier blog:

Basic Operating Principle of an Inductive Proximity Sensor

Manufacturers Track Goods, Reduce Errors, Decrease Workload with RFID

More and more, retailer sellers are starting to require that manufacturers place RFID tags on their products before they leave the production facility and are shipped to those retail locations. From high-end electronics all the way down to socks and underwear are being tagged.

These tags are normally supplied by the retailer or through a contracted third party. Typically disposable UHF paper tags, they are only printed with a TID number and a unique EPC that may or may not correspond to the UPC and barcode that was used in the past. Most cases I have seen require that the UPC and a barcode be printed on these RFID tags so there is information available to the human eye and a barcode scanner when used.

While this is being asked for by the retailers, manufacturers can use these tags to their own advantage to track what products are going out to their shipping departments and in what quantities. This eliminates human error in the tracking process, something that has been a problem in the past, while also reducing workload as boxes of finished goods no longer must be opened, counted and inspected for accuracy.

A well-designed RFID portal for these items to pass through can scan for quantities and variances in types of items in boxes as they pass through the portal. Boxes that do not pass the scan criteria are then directed off to another area for rework and reevaluation. Using human inspection for just the boxes that do not pass the RFID scan greatly reduces the labor effort and expedites the shipping process.

I recently assisted with a manufacturer in the garment industry who was having to tag his garments for a major retailer with RFID tags that had the UPC and a barcode printed on them. The tags were supplied through the retailer and the EPCs on the tags were quite different then the UPC numbers printed on them.

The manufacturer wanted to know how many garments of each type were in each box. Testing showed that this could be done by creating a check point on his conveyor system and placing UHF RFID antennas in appropriate locations to ensure that all the garments in the box were detected and identified.

In this case, the manufacturer wanted was a simple stand-alone system that would display a count of different types of garments. An operator reviewed the results on a display and decided based on the results whether to accept the box and let the conveyor forward it to shipping or reject it and divert it to another conveyor line for inspection and adjustment.

While this system proved to be relatively simple and inexpensive, it satisfied the desires of the manufacturer. It is, however, possible to connect an RFID inspection station to a manufacturing information system that would know what to expect in each box and could automatically accept or reject boxes based on the results of the scans without human intervention and/or human error.

Chain of Support: The Link to Performance During Emergencies

What businesses do in the face of adversity can expose what they are at their core. Adversity is like a catalyst to an otherwise stable state. It forces a reaction. In a chemical reaction, we can predict how a known catalyst will affect a known solution. However, companies are much more unpredictable.

As automation takes center stage in a world of decreased human to human contact and tighter labor budgets, it is critical to understand who your automation partners really are. Who are the humans behind the brands, and what processes do they have in place to respond to emergencies? In manufacturing, downtime, whether planned or not, must be minimized.

One thing we know for certain about adversity is it will happen. Know how your automation partners will respond to a problem. Have them explain their plan to you before the problem occurs. Them having a plan, and you being aware of it, minimizes the impact on production. You can’t wait until a situation occurs during third shift on a Friday to have the discussion.

Knowing the answers to key questions ahead of time can advert a crisis. Who do you call when you need a replacement part? Are they local? How quickly can they respond? If that first person isn’t available what is my next step? When can someone be available? Can they come on site or will they support remotely? How long will it take to get a replacement part? Do you offer assistance with deployment?

The answers to these questions make up the chain of support for a product. Frankly, these answers are the things that truly delineate automation companies. You can always count on innovative technologies to be released to address quality, conformance and efficiency, but you have to make sure there is a secure chain of support behind those technologies. Companies that can clearly explain what this looks like are the ones who will be around for the long haul. Afterall, it’s what we do in the face of adversity that defines who we are.

Beyond the Human Eye

Have you ever had to squint, strain, adjust your glasses, or just ask for someone with better vision to help read something for you? Now imagine having to adjust your eyesight 10 times a second. This is the power of machine vision. It can adjust, illuminate, filter, focus, read, and relay information that our eyes struggle with. Although the technology is 30 years old, machine vision is still in its early stages of adoption within the industrial space. In the past, machine vision was ‘nice to have’ but not really a ‘need to have’ technology because of costs, and the technology still not being refined. As traceability, human error proofing, and advanced applications grow more common, machine vision has found its rhythm within factory automation. It has evolved into a robust technology eager to solve advanced applications.

Take, for example, the accurate reading, validation, and logging of a date located on the concaved bottom of an aluminum can. Sometimes, nearly impossible to see with the human eye without some straining involved, it is completely necessary to ensure it is there to be able to sell the product. What would be your solution to ensuring the date stamp is there? Having the employee with the best eyes validate each can off the line? Using more ink and taking longer to print a larger code? Maybe adding a step by putting a black on white contrasting sticker on the bottom that could fall off? All of these would work but at what cost? A better solution is using a device easily capable of reading several cans a second even on a shiny, poor angled surface and saving a ton of unnecessary time and steps.

Machine vison is not magic; it is science. By combining high end image sensors, advanced algorithms, and trained vision specialists, an application like our aluminum can example can be solved in minutes and run forever, all while saving you time and money. In Figure 1 you can see the can’s code is lightly printed and overcome by any lighting due to hotspots from the angle of the can. In Figure 2 we have filtered out some of the glare, better defined the date through software, and validate the date is printed and correct.

Take a moment to imagine all the possibilities machine vision can open for your production process and the pain points it can alleviate. The technology is ready, are you?

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Reduce the Number of Ethernet Nodes on Your Network Using IO-Link

Manufacturers have been using industrial Ethernet protocols as their controls network since the early 1990s. Industrial Ethernet protocols such as Ethernet/IP, ProfiNet, and Modbus TCP were preferred over fieldbus protocols because they offered the benefits of higher bandwidth, open connectivity and standardization, all while using the same Ethernet hardware as the office IT network. Being standard Ethernet also allows you to remotely monitor individual Ethernet devices over the network for diagnostics and alarms, delivering greater visibility of the manufacturing data.

With Ethernet as the key technology for Industry 4.0 and digitalization, more and more devices will have Ethernet capabilities. Typical industrial Ethernet nodes on a plant floor could include PLC controllers, robots, I/O devices for sensors, actuators, flowmeters, transducers and manifolds. While, it’s great getting all the data and diagnostics of the entire manufacturing process, having every device connected via Ethernet has some downfalls. It can lead to larger Ethernet networks, which can mean more costs in hardware such as routers, switches and Ethernet cables, and some Ethernet software license costs are based on the number of Ethernet nodes being used in the network.

Also, as more Ethernet devices are added to a network, the Ethernet network itself can get more complex. Each individual Ethernet device requires an IP address. If an Ethernet node stopped working and needed to be replaced, an operator would need to know the previous IP address of the device and have quick access to the manual with instructions on how to assign the previous IP address to the new device. Someone must also manage the IP addresses on the network. There will need to be a list of the IP addresses on the network as well as the available ones, so when a new Ethernet device is added to the network, a duplicate address is not use

One way to reduce the number of Ethernet nodes while still getting device data and diagnostics is by using IO-Link for field device communications. IO-Link is an open point-to-point communication standard for sensors and actuators published by IEC (International Electrotechnical Commission) as IEC 61131-9. Since it’s fieldbus and manufacturer independent, there is a long list of manufacturer devices that come with IO-Link. Each IO-Link device can then be brought back to a single Ethernet node, through an IO-Link to Ethernet gateway. Since it’s open technology, there are also multiple manufacturers that make different IO-Link to industrial Ethernet gateways.

On the IO-Link to Ethernet gateway, each channel has an IO-Link master chipset. It is designed to automatically communicate and provide data as soon as an IO-Link device is connected to a port. So, there is no addressing or additional setup required. IO-Link is point to point, so it’s always a single IO-Link device connected to a single port on the gateway using a standard sensor cable. Depending on the number of IO-Link devices to be connected to a single Ethernet node, IO-Link gateways can come in 4, 8 or 16 device channels. This graphic (image 1) shows six IO-Link devices connected to a single 8-channel Ethernet gateway. This gateway then communicates back to the Ethernet PLC controller as a single IP address with a standard Ethernet cable. Without using IO-Link, this might require all six devices to be industrial Ethernet devices. Each device would have its own IP address to set up, along with six Ethernet cables going back to a 6-port managed switch before going to the PLC controller.

 

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Image 1: Six IO-Link devices connected to a single 8-channel Ethernet gateway.

IO-Link Devices Connected:

  1. Device I/O Hub used to connect to 16 standard discrete sensors/photoeyes.
  2. Valve Manifold used to control up to 24 coils.
  3. Visual Indicator Light
  4. RFID Processor System
  5. Pressure Sensor
  6. IO-Link to Standard Analog (0-10V or 4-20ma) Converter

Error Proof Stamping Applications with Pressure Sensors

When improving product quality or production efficiency, manufacturing engineers typically turn to automation solutions to error proof and improve their application. In stamping applications, that often leads to adding sensors to help detect the presence of a material or a feature in a part being formed, for example, a hole in a part. In the stamping world, this can be referred to as “In-Die Sensing” or “Die Protection.” The term “Die Protection” is used because if the sensors do not see the material in the correct location when forming, then it could cause a die crash. The cost of a die crash can add up quickly. Not only is there lost production time, but also damage to the die that can be extremely costly to repair. Typically, several sensors are used throughout the die to look for material or features in the material at different locations, to make sure the material is present to protect the die. Manufacturing engineers tend to use photoelectric and/or inductive proximity sensors in these applications; however, pressure sensors are a cost-effective and straightforward alternative.

In today’s stamping applications, manufacturing engineers want to stamp parts faster while reducing downtime and scrap. One growing trend in press shops is the addition of nitrogen on the dies. By adding nitrogen-filled gas springs and/or nitrogen gas-filled lifters, the press can run faster and cycle parts through quicker.

Typically, the die is charged with nitrogen before the press starts running parts. Today, many stamping plants rely on an analog dial gauge (image 1) to determine if there is sufficient nitrogen pressure to operate safely. When a new die is set in the press, someone must look at the gauge and make sure it is correct before running the press. There is no type of signal or feedback from this gauge to the PLC or the press; therefore, no real error proofing method is in place to notify the operator if the pressure rating is correct or even present before starting the press. If the operator starts running the press without any nitrogen for the springs, then it will not cycle the material and can cause a crash.

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Another, likely more significant problem engineers face is a hole forming in one of the hoses while they are running. A very small hole in a hose may not be noticeable to the operator and may not even show up on the analog dial gauge. Without this feedback from the gauge, the press will continue to run and increase the likelihood that the parts will be stamped and be out of specification, causing unnecessary scrap. Scrap costs can be quite large and grow larger until the leak is discovered. Additionally, if the material cannot move through the press properly because of a lack of nitrogen pressure to the springs or lifters, it could cause material to back up and cause a crash.

By using a pressure sensor, you can set high and low pressure settings that will give an output when either of those is reached. The outputs can be discrete, analog, or IO-Link, and they can be tied to your PLC to trigger an alarm for the operator, send an alert to the HMI, or even stop the press. You can also have the PLC make sure pressure is present before starting the press to verify it was adequately charged with nitrogen during set up.

Adding an electronic pressure sensor to monitor the nitrogen pressure is a simple and cost-effective way to error proof this application and avoid costly problems.