The Need for Data and System Interoperability in Smart Manufacturing

As technology advances at a faster pace and the world becomes flatter, manufacturing operations are generally focused on efficient production to maximize profitability for the organization. In the new era of industrial automation and smart manufacturing, organizations are turning to data generated on their plant floors to make sound decisions about production and process improvements.

Smart manufacturing improvements can be divided roughly into six different segments: Predictive Analytics, Track and Trace, Error Proofing, Predictive Maintenance, Ease of Troubleshooting, and Remote Monitoring.IOLink-SmartManufacturing_blog-01To implement any or all of these improvements requires interoperable systems that can communicate effectively and sensors and devices with the ability to provide the data required to achieve the manufacturer’s goals. For example, if the goal is to have error free change-overs between production cycles, then feedback systems that include identification of change parts, measurements for machine alignment changes, or even point of use indication for operators may be required.  Similarly, to implement predictive maintenance, systems require devices that provide alerts or information about their health or overall system health.

Traditional control system integration methods that rely heavily on discrete or analog (or both) modes of communication are limited to specific operations. For example, a 4-20mA measurement device would only communicate a signal between 4-20mA. When it goes beyond those limits there is a failure in communication, in the device or in the system. Identifying that failure requires manual intervention for debugging the problem and wastes precious time on the manufacturing floor.

The question then becomes, why not utilize only sensors and devices with networking ability such as a fieldbus node? This could solve the data and interoperability problems, but it isn’t an ideal solution:

  • Most fieldbuses do not integrate power and hence require devices to have separate power drops making the devices bulkier.
  • Multiple fieldbuses in the plant on different machines requires the devices to support multiple fieldbus/network protocols. This can be cost prohibitive, otherwise the manufacturer will need to stock all varieties of the same sensor.
  • Several of the commonly used fieldbuses have limitations on the number nodes you can add — in general 256 nodes is capacity for a subnet. Additional nodes requires new expensive switches and other hardware.

IOLink-SmartManufacturing_blog-02IO-Link provides one standard device level communication that is smart in nature and network independent, thus it enables interoperability throughout the controls pyramid making it the most suitable choice for smart manufacturing.

We will go over more specific details on why IO-Link is the best suited technology for smart manufacturing in next week’s blog.

 

Safely Switch Off Cylinders While Transmitting Field Data

Is it possible to safely switch off cylinders while simultaneously transmitting field data and set up the system in accordance with standards? Yes!

In order to rule out a safety-critical fault between adjacent printed circuit board tracks/contact points (short circuit) according to DIN EN ISO 13849, clearance and creepage distances must be considered. One way to eliminate faults is to provide galvanic isolation by not interconnecting safety-relevant circuits/segments. This means  charge carriers from one segment cannot switch over to the other, and the separation makes it possible to connect the safety world with automation — with IO-Link. Safely switching off actuators and simultaneously collecting sensor signals reliably via IO-Link is possible with just one module. To further benefit from IO-Link and ensure safety at the same time, Balluff’s I/O module is galvanically isolated with a sensor and an actuator segment. The two circuits of the segments are not interconnected, and the actuator segment can be safely switched off without affecting the sensors. Important sensor data can still be monitoring and communicated.

The topological structure and the application of this safety function is shown in this figure as an example:

2D-SAGT-Betriebsanleitung_v2

  1. A PLC is connected to an IO-Link master module via a fieldbus system.
  2. The IO-Link master is the interface to all I/O modules (IO-Link sensor/actuator hubs) or other devices, such as IO-Link sensors. The IO-Link communication takes place via a standardized M12 connector.
  3. Binary switching elements can be connected to the galvanically isolated sensor/actuator hub (BNI IOL-355). The four connection ports on the left correspond to the sensor segment and the four ports on the right correspond to the actuator segment. Communication of the states is done via IO-Link.
  4. The power supply for both segments takes place via a 7/8″ connection, whereby attention must be paid to potential separated routing of the sensor and actuator circuits. Both the power supply unit itself and the wiring to the IO-Link device with the two segments must also ensure external galvanic isolation. This is made possible by separating the lines with a splitter.
  5. An external safety device is required to safely interrupt the supply voltage of the actuator segment (four ports simultaneously). Thus, the module can implement safety functions up to SIL2 according to EN62061/PLd and ISO 13849.  For example, this can happen through the use of a safety relay, whereby the power supply is safely disconnected after actuation of peripheral safety devices (such as emergency stops and door switches). At the same time, the sensor segment remains active and can provide important information from the field devices.

The module can handle up to eight digital inputs and outputs. If the IO-Link connection is interrupted, the outputs assume predefined states that are retained until the IO-Link connection is restored. Once the connection is restored, this unique state of the machine can be used to continue production directly without a reference run.

An application example for the interaction of sensors and actuators in a safety environment is the pneumatic clamping device of a workpiece holder. The position feedback of the cylinders is collected by the sensor segment, while at the same time the actuator segment can be switched off safely via its separately switchable safety circuit. If the sensor side is not required for application-related reasons, galvanically isolated IO-Link modules are also available with only actuator segments (BNI IOL 252/256). An isolated shutdown can protect up to two safety areas separately.

 

Non-Contact Transmission of Power & Data on Transfer Rails & Grippers

For press shops utilizing transfer rail systems, fixed sensor connections regularly cause frustration. Cables and contacts are often subject to heavy strain. Cables can wear out and break, damaged pins or mechanical collisions can cause hours of machine downtime, and the replacement of large multi-pin connectors comes at a high cost.

Inductive couplers offer an ideal solution: By using these non-contact, wear-free products you can eliminate pin connections and simplify job changeovers on the press. Inductive couplers transfer signals and power contact-free over an air gap. The quick-disconnect units are easy to use and require no maintenance, enabling you to meet new demands quickly. Mechanical wear is a thing of the past. This increases system availability, reduces cycle time and enhances the flexibility of workflow processes.

Inductive coupling example

Replace pin connections for transfer rails

Typically, two pin-based connectors connect the transfer rail to the transfer system on the press. The connections are on both the feed and exit sides of the rail to the control. If there is any misalignment of the connections, damage regularly occurs. By replacing the connectors with pin-free inductive couplers, the connections are simplified and repair work is minimized. Additionally you don’t have open pins exposed to the environment (dust, water, oil) that can also cause nuisances in the connection process.

Replace pin connections for grippers

To connect the transfer rail on each gripper, normally a pin-based connector is used. As the grippers are changed on each tooling change, the connectors become worn and damaged with regularity. By replacing the pin connector with non-contact inductive couplers, the two sensor signals are maintained but the maintenance of these connections is reduced dramatically. An additional “in-zone signal” verifies that the gripper is installed and connected. This provides assurance during operation.

Inductive couplers offer IO-Link functionality

Inductive coupling with IO-Link technology adds more benefits besides replacing the pin coupling. It allows users to transfer up to 32 bytes of data in addition to power for actuation or sensors. If you connect IO-Link enabled I/O hubs or valve connectors to the remote side, you can also store identification data on the IO-Link hub or valve. When the connection is established, the controller can request the identification data from the tool to ensure that the system is utilizing the correct tool for the upcoming process.

With pin based coupling you needed up to 4-5 seconds to first engage the tool and to mate the two ends of the pin couplers and then request the identification. With inductive couplers, the base only needs to be brought closer to the remote so that you quickly couple and identify the tool before engaging the tool — this takes less than a second. Additionally the base and remote do not need to be well aligned to couple. Misalignment up to 15-20 degrees of angular offset or 2-4 mm of axial offset still provides functionality.

The benefits at a glance

  • Power and signals transfer with pin-less connectivity
  • Reduced downtime due to rail or gripper repair
  • Know that the gripper is present and powered with in-zone signal
  • Inform the controller that the rail has power and connectivity to the sensors

To decide the right coupler for your next application visit www.balluff.com.

 

Industrial Safety Protocols

There are typically three or more communication levels in the modern factory which consist of:

  • Enterprise level (Ethernet)
  • Control level (Ethernet based industrial protocol)
  • Device/sensor level (various technologies)

IO-Link

The widespread use of control and device level communications for standard (non-safety) industrial applications led to a desire for similar communications for safety. We now have safety versions of the most popular industrial control level protocols, these make it possible to have safety and standard communications on the same physical media (with the appropriate safety hardware implemented for connectivity and control). In a similar manner, device level safety protocols are emerging to allow standard and safety communications over the same media. Safety Over IO-Link and AS-i Safety At Work are two examples.

This table lists the most common safety control level protocols with their Ethernet-based industrial “parent” protocols and the governing organizations:

chart1

And this table lists some of the emerging, more well-known, safety device level protocols with their related standard protocols and the governing or leading organizations:

Chart2
* Safety Over IO-Link is the first implementation of safety and IO-Link. The specification for IO-Link Safety was released recently and devices are not yet available.

Ethernet-based safety protocols are capable of high speed and high data transmission, they are ideal for exchanging data between higher level devices such as safety PLCs, drives, CNCs, HMIs, motion controllers, remote safety I/O and advanced safety devices. Device level protocol connections are physically smaller, much less expensive and do not use up IP addresses, but they also carry less data and cover shorter distances than Ethernet based protocols. They are ideal for connecting small, low cost devices such as E-stops, safety switches and simple safety light curtains.

As with standard protocols, neither a control level safety protocol, nor a device level safety protocol can meet all needs, therefore cost/performance considerations drive a “multi-level” communications approach for safety. This means a combined solution may be the best fit for many safety and standard communications applications.

A multi-level approach has many advantages for customers seeking a cost-effective, comprehensive safety and standard control and device solution which can also support their IIoT needs. Users can optimize their safety communications solutions, balancing cost, data and speed requirements.

Connecting Fluid Power to the Industrial IoT and Industry 4.0

The next industrial revolution has already begun. To remain a viable business, it’s time to invest in IIoT and Industry 4.0 applications, regardless of whether you are a “mechanical-only” company or not.Industry 4.0 & Industrial IoT

Industrial Internet of Things

IIoT is simply about connecting devices on the plant floor to a network. These connections provide new ways to generate and collect useful data. This network can provide visibility down into the machine, enabling predictive maintenance and big data analytics. With IIoT, we are able to improve overall equipment effectiveness and provide new insights into our business.

Industry 4.0

On a grander scale, Industry 4.0 is a blend of digitalization, new technology and practical decisions to improve manufacturing. Industry 4.0 aims to achieve unprecedented flexibility, efficient production and visibility at every level of production. Industry 4.0 has impact throughout our processes and across the supply chain. Its philosophy blends lean initiatives, automation, technology, materials, downtime reduction upgrades, and investments in overall equipment effectiveness. This philosophy keeps the current generation of manufacturers competitive in a global market. While the German government set this precedent for Industry 4.0, the entire manufacturing world must now take on this challenge.

Implementing IIoT and Industry 4.0

Standard systems like hydraulic power units (HPUs) are receiving a major boost by becoming IIoT-ready. Traditional on/off flow or pressure switches are upgrading to provide information beyond the simple switch points. In addition, analog devices like temperature, pressure, flow, and level transducers can become IIoT-ready through open standard technologies like IO-Link. These technologies add additional value by incorporating easy-to-report parameters, diagnostics, events and warnings. A standard HPU can become a smart power unit with minimal modification.

The value of IIoT increases with predictive maintenance, remote monitoring and ease of troubleshooting. Imagine not having to climb down into the oil-drenched pit of a stamping press to trouble shoot an issue. With IIoT-ready technologies, we can connect to the devices and know exactly what needs fixing. In addition, we can possibly predict the failure before it occurs. This can dramatically reduce machine downtime as well as the time spent in hazardous locations.

Selecting IIoT-ready technologies is only one step of the program to fully leverage the value of Industry 4.0. We must also analyze processes and determine how to implement flexibility into production. After that, we must then discuss where automation technology makes sense to support lean processes. Manufacturers can see into every aspect of their production while manufacturing hundreds of variations of product in the same line, all while assuring quality standards with virtually zero machine downtime.

The difference between Industry 4.0 and IIoT

Industry 4.0 is a cultural philosophy about how we can use increased visibility, flexibility and efficiency to be more competitive. IIoT’s connectivity is an enabling force for Industry 4.0. IIoT connects our devices, our data, our machines and our people to the advantage of our company and customers.  By embracing both, it is easier to achieve positive results and sustain global competitiveness.

Article originally posted on Hydraulics & Pneumatics.

Installation and device replacement – easy and safe

The development and design of a machine is followed by the assembly and commissioning phase. Commissioning is especially time consuming, but the replacement of components or devices can be so as well.

This often raises the question of how to simplify commissioning and optimize component replacement.

The answer is provided by the IO-Link communication interface. IO-Link is the first globally standardized IO technology (IEC 61131-9) that communicates from the controller down to the lowest level.

But how exactly does this help with commissioning and component replacement? This is very simple and will be explained now. Let’s start first with the assembly, installation and commissioning phase.

Easy installation

During installation, the individual components must be electrically connected to each other. While fieldbus use has simplified the installation process, generally speaking, fieldbus cables have a low signal level, are susceptible to interference, have little flexibility, and are expensive due to their shielding. This is where IO-Link comes into play. Because the weaknesses of a fieldbus protocol are negligible with IO-Link.

Included in an IO-Link system are an IO-Link master and one or several IO-Link devices such as sensors or actuators. The IO-Link master is the interface to the controller (PLC) and takes over communication with connected IO-Link devices. The interface uses unshielded, three- or four-conductor standard industrial cables. Therefore the standard communication interface can be integrated into the fieldbus world without effort. Even complex components can be easily connected in this way. In addition, the standard industrial cables are highly flexible and suitable for many bending cycles. Three wires are the standard for the communication between the devices and the IO-Link master and for the power supply voltage. These are easy to connect, extremely cost-effective and their connection is standardized with M5, M8 or M12 connectors.

The commissioning will also be supported by IO-Link. The devices can be parameterized quickly and easily through parameter maintenance or duplication. Annoying manual adjustment of the sensors and actuators is no longer necessary. This saves money and avoids errors. The parameters of the individual devices are stored in the PLC or directly in the IO-Link master and can, therefore, be written directly to the sensor.

Now that we have clarified the advantages of IO-Link during commissioning, we will take a look at the replacement of components.

Communication with IO-Link

Save device replacement during operation

A sensor replacement directly leads to machine downtime. IO-Link enables quick and error-free replacement of sensors. The parameters of a replaced IO-Link sensor are automatically written from the IO-Link master or the PLC to the new sensor. The accessibility of the sensor does not play a major role anymore. In addition, IO-Link devices cannot be mixed up, since they are automatically identifiable via IO-Link.

Efficient format and recipe changes

IO-Link offers ideal properties that are predestined for format adjustment: sufficient speed, full access to all parameters, automatic configuration, and absolute transmission of the measured values. This eliminates the need for time-consuming reference runs. Since the machine control remains permanently traceable, the effort required for error-prone written paper documentation is also saved. Format changes and recipe changes can be carried out centrally via the function blocks of the PLC.

To learn more about the advantages of IO-Link, visit balluff.us/io-link.

 

Back to the Basics: IO-Link

In the last post about the Basics of Automation, we learned how distances, travel, angles and pressures can be measured contactlessly, whether linear or rotary. In this blog, let’s take a closer look at IO-Link technology.

Throughout the history of manufacturing, as the level of automation increased, the demand for intelligent field devices grew. A variety of interfaces with different mechanical and electrical characteristics were created, and the need for standardization grew. The cooperative work of several companies developed the viable solution. Like  USB in the PC world, IO-Link in automation leads to a considerable simplification of installation with simultaneously extended diagnostics and parameterization capability.

IO-Link 1

It’s a worldwide standardized I/O technology according to IEC 61131-9, in order to communicate from the control to the lowest level of automation. The universal interface is a fieldbus independent point-to-point connection that works with an unshielded industrial cable. The IO-Link Community founded in 2006, consisting of leading automation manufacturers, promotes IO-Link with the acronym “”USE””:

  • Universal – IO-Link is an international standard (IEC 61131-9)
  • Smart – IO-Link enables diagnostics and parameter-setting of devices
  • Easy – IO-Link provides great simplification and cost reduction

System Components

IO-Link master
Also mentioned as the heart of the IO-Link installation, it communicates with the controller via the respective fieldbus as well as downward using IO-Link to the sensor/actuator level.

Sensors and Actuators
The IO-Link capable intelligent sensors and actuators are connected directly to the IO-Link master via IO-Link. This enables the simplest installation, the best signal quality, parameterization and diagnostics.

Hubs
The sensor/actuator hub exchanges signals with the binary and/or analog sensors and actuators and communicates with the IO-Link master.

IO-Link 2

To learn more about the Basics of Automation, visit www.balluff.com.

IO-Link vs. Analog in Measurement Applications

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

1

Fewer data errors, at lower cost

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

2

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

3

Less sensor programming required

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

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

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

Diagnostic data included

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

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

4

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

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

Set your sights on IO-Link for machine vision products

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

PLC Gateway-Modus

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

Rainer1

Camera-Modus – without PLC

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

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

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

 

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

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

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

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

Precisely detecting point levels

For point level detection we have three different options.

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

Image 1
One point level detection through transparent container walls

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

Figure 2
Minimum/maximum level detection with capacitive sensors

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

Figure 3
Capacitive sensors mounted inside the tank

Continuous level sensing

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

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

Figure 4
Continuous level detection with a capacitive sensor head

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

Figure 5
Level detection via magnetostrictive sensing principle

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

Figure 6
Level detection via hydrostatic pressure sensor

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

Figure 7
Level detection via ultrasonic sensor

Product bundle for level monitoring in storage tanks

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

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

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

Figure 8
Level monitoring in storage tanks

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