Open automation technology with EtherCAT: perfectly suited to the handling of plastic parts

The PC-based control principle

With PC-based control technology, we offer comprehensive system solutions in various performance classes for the automation of all types of plastics machines. The basic principle is based on a powerful industrial PC, a high-performance fieldbus connection with the connected peripheral devices for sensors and actuators, and the software for engineering and real-time control. The control platform is supplemented by an extensive portfolio of drive components. TwinCAT automation software bundles all necessary functionalities such as PLC, motion control, robotics, measurement technology, image processing, and HMI. Our technology is based on IT standards and has the necessary openness to implement intelligent production concepts according to Industrie 4.0.

Due to the high performance of modern processors, which we install in all of our PC series, computationally intensive applications can easily be integrated into the control platform. Plastics machine manufacturers benefit from the continuous increase in the performance of PC processors: Shorter sampling times are already increasing the quality of the end product today and will be the requirement for the realization of self-learning machines in the future. The possibility, for example, to completely simulate an injection molding machine in the virtual design process saves time during development and commissioning.

EtherCAT: World standard for plastics machines

The EtherCAT technology was launched on the market by us in 2003 and made available as an open standard for automation technology. With outstanding performance, flexible choice of topology, comprehensive diagnostics and simple configuration, EtherCAT is ideally suited for use in plastics machines. We offer the largest number of EtherCAT-compatible automation modules for I/Os and for drive technology.

EtherCAT is one of the most widely used standards in plastics technology. A large number of EtherCAT-compatible sensors and actuators are available on the market, which guarantees a high level of investment security. Particularly interesting for electrically driven injection molding machines is the problem-free connection of drives from third-party suppliers. Other fieldbus systems can also be integrated as communication layers via EtherCAT.

The fast and high-precision Beckhoff control solution eXtreme Fast Control (XFC) is based on EtherCAT and special I/O modules optimized for XFC that record signals or trigger actions with high accuracy. With I/O response times under 100 μs, XFC enables very fast and extremely deterministic reactions and thus contributes to process optimization.

TwinSAFE: The open and scalable safety technology

With TwinSAFE, we have implemented a consistent safety concept that integrates safe functionalities into the non-safety-related control architecture. Separate safety controllers are thus superfluous. The typical safety functions can be programmed and configured on the EL6910 TwinSAFE Logic or the compact EK1960 safety controller, based on standard safety function blocks according to the safety requirements. The Beckhoff safety solution accelerates the engineering process, as the safety-related requirements of different machine configurations can be realized by software. All our safety controllers are suitable for applications up to SIL 3 according to IEC 61508 or PLe of ISO 13849-1 and meet the EN 201 standard for injection molding machines.

Safety technology seamlessly integrates into the terminal segment via the TwinSAFE I/O modules, whereby safe signals can be mixed with standard signals as required. This benefits, for example, blow molding machines or production cells with control cabinets in different installation locations. Due to its scalability, the Beckhoff safety solution is suitable for expansive, complex systems with distributed I/Os as well as for small injection molding and blow molding machines. One safety logic is sufficient here to realize the complete safety technology. The compact EK1960 safety controller is particularly suitable for injection molding machines with hydraulic and/or electric drives. It allows the direct control of digital switching valves with a load of 2 A, such as those used in core pullers. With the help of the TwinSAFE SC technology, signals with a low safety level can be used redundantly for safety tasks.

EtherCAT I/O modules integrate temperature control, energy measurement and safety technology into the control platform

In 1995, Beckhoff launched the Bus Terminal, which has since become one of the most important technology standards in automation technology. This was followed in 2003 by the development of the EtherCAT fast communication system. Launched by Beckhoff as an open system, it became a global standard in automation within a few years. An extensive EtherCAT I/O Terminal portfolio is available to users that is extremely well suited for automating every functionality in plastics machines and their peripherals in terms of both its performance and variance.

• EL3318 for temperature measurement
  The EL3318 EtherCAT Terminal is ideal for temperature measurement via thermocouples. The 8-channel input terminal with integrated cold junction compensation is very compact in its design and measures temperatures with high accuracy and high signal-to-noise ratio.
• EL3403 and EL3446 for power measurement
  The EL3403 three-phase power measurement terminal can be used to measure and optimize the power consumption of a plastics machine. In conjunction with the TwinCAT Plastic Processing Framework, the EL3403 is used for the cost-effective Condition Monitoring of the heating tapes through sequentially alternating testing in operation. In traditional control structures, the power measurement terminal can also be used for current measurement. The EL3446 is available for simple monitoring of the heating tape function. In combination with the voltage measurement in just one power measurement terminal, the power consumption of individual machine components can be recorded cost-effectively by means of current measurement. The Beckhoff SCT current transformers (SCT2xxx, SCT1xxxx) enable assembly of the appropriate combination of sensor and power measuring terminal without requiring detailed knowledge.
• EL3255 for position detection
  The EL3255 EtherCAT Terminal allows potentiometric position detection. Due to its integrated power supply, the terminal delivers precise results (voltage values) even in environments with high interference fields. The EL3255 is particularly suitable for injection molding and blow molding machines with hydraulic drive technology.
• EL6224 IO-Link terminal
  IO-Link is an inexpensive fieldbus for the reading of sensors with low real-time requirements. A preferred application, for example in extrusion, is the reading of melt pressure and melt temperature via the EL6224.
• TwinSAFE terminals for integrating safety technology into the controllerDue to its scalability, the Beckhoff safety solution is suitable for expansive, complex systems with distributed I/Os as well as for small injection molding and blow molding machines. One safety logic is sufficient here to realize the complete safety technology. The compact EK1960 safety controller is particularly suitable for injection molding machines with hydraulic and/or electric drives. It allows the direct control of digital switching valves with a load of 2 A, such as those used in core pullers.

Universal EtherCAT for the IP67 world

With the EtherCAT Box, EtherCAT technology is used without a control cabinet. The modules from the IP67 series have an integrated direct EtherCAT interface, so that the high performance is retained right down to each module. In the IP67 world, this enables fast process data communication with XFC, high-precision measurement technology and integrated drive technology functions directly in the field. The robust design of the EtherCAT Box modules enables them to be used directly at the machine. Control cabinets and terminal boxes are now no longer required. In addition to the sturdy M12 screw connectors, D-Sub connectors, which are perfectly suited for handling applications, are also available for cost-sensitive applications.

• With the EP3744 EtherCAT Box, pneumatic pressure monitoring for the gripper elements can be implemented in handling applications; at the same time, six digital inputs can be read in.
• In the EP1816, the acquisition of 16 digital inputs is combined with the measurement of acceleration forces in three axes.
• The EP3752 enables the measurement of acceleration forces without additional inputs. The measured values of the accelerometers can be used for the acquisition of the mass forces, e.g., on machine bodies or for control concepts with jerk compensation on handling devices.
• The EP3314 EtherCAT Box is suitable for the acquisition of process temperatures directly at the point where they arise. It increases measuring accuracy and saves having to use compensating cables for the thermocouples.
• The FM3312 or FM3332 Fieldbus Modules in a sturdy metal housing are particularly suitable for temperature measurement on injection molds or nozzles in extrusion lines. Up to 32 temperature channels can be contained in one industrial connector. Operational reliability is additionally ensured by reverse polarity protection against phase voltage.
• With the EP3356, the high-precision evaluation of load cells is possible, which is required in extruder applications for dosing and melt throughput measurement.

Drive systems for highly dynamic positioning tasks

In combination with the motion control solutions in the TwinCAT automation software, Beckhoff drive technology represents a complete drive system for all applications in plastics technology. With EtherCAT as a fast communication system, it is suitable for single and multi-axis positioning tasks with highly dynamic requirements. Due to its scalability, the Beckhoff drive technology enables machine manufacturers to design their drive solution to suit the required performance.

The AX5000 and AX8000 servo drive series offer maximum performance and dynamics with powerful EtherCAT system communication. The integrated, fast control technology of the AX series supports the execution of high-precision positioning tasks, such as those required in the field of film production: The smoothing rollers, which smooth the extruded film before winding, must be adjustable in the submillimeter range. The AX5000 offers the optimal solution for ultra-fast removal processes. The flexible concept of the AX5000 with 1- and 2-channel units as well as the variable motor power ensure a cost-optimized design. The drives from the AX8000 series are predestined for compact, modular drive units and for Cartesian handling devices.

In the lower performance range, the EtherCAT servo terminals, which offer a complete servo drive in the standard terminal housing, represent a drive solution that is both compact and inexpensive for low part weights or for additional units with low power consumption.

Modular design concept for maximum flexibility and space savings

The AMP8000 integrates the servo drive directly into the servomotor in a very compact design. By relocating the power electronics into the machine, the space requirement in the control cabinet is reduced to a single coupling module, which supplies several distributed servo drives with only one cable via a distribution module. A further expansion stage completely eliminates the control cabinet space required for the drive technology. Whereas the connection of the drives to the control cabinet is reduced to only one cable with the coupling modules, it is completely eliminated when using the AMP8620 power supply module.

The AMP8000 is suitable for a wide range of applications in plastics processing. Handling devices for injection molding machines or blow molding machines can be attached with the AMP8000 without an additional control cabinet. This also applies to complete production cells with a typically limited footprint.

Movement with six degrees of freedom ensures maximum flexibility in positioning

With the XPlanar system, Beckhoff opens up new paths in plant design: the planar movers hover jerk-free and contact-free over planar motor tiles in any desired arrangement. They can be moved two-dimensionally at speeds of up to 2 m/s, with 2 g acceleration and 50 µm positioning accuracy, silently and without abrasion.

The planar motor system, which is scalable to suit needs, can significantly simplify the design of machines and plants and enables new freedoms in machine design. Due to the enormously flexible mover positioning and the very high movement dynamics, it is possible, for example, to divide product flows very easily and individually. Where robots or other inflexible mechanical devices have been used up to now, the XPlanar offers an efficient and flexible solution. The non-contact movement of the movers also eliminates wear, emissions and the carry-over of impurities. The XPlanar is therefore also ideally suited for applications with high hygiene standards, such as those that must be adhered to when transporting sensitive workpieces.

TwinCAT: the integrated engineering and control platform

TwinCAT integrates all engineering and runtime processes on a central software platform. This applies to programming, configuration, real-time environment and all runtime modules. By programming in the common IEC PLC dialects and integrating C/C++ algorithms, machine manufacturers can freely choose the most suitable programming method depending on the qualifications of the programmers, the service strategy and the need to protect expertise. With the integration of MATLAB^® and Simulink^®, controller concepts are developed based on models, thus contributing to virtual machine design. By using Microsoft Visual Studio as integrated programmer workbench, different version control systems are supported and teamwork is simplified. For series production, TwinCAT offers open interfaces for the integration of commercial IT systems for machine program generation.

• Extensive TwinCAT libraries for motion control save development time thanks to tested and optimized algorithms. The TwinCAT PTP and TwinCAT NC I supplements are ideally suited for handling applications with Cartesian robots. Ready-to-run solutions are available with TwinCAT Kinematic Transformation for other robot kinematics, such as SCARA, Delta and articulated arm.
• Commissioning and service processes are accelerated and improved with TwinCAT Scope, a software oscilloscope fully integrated into the TwinCAT system architecture, and thus contribute to increasing machine quality.
• TwinSAFE software-based safety technology simplifies the wiring of complex systems; variants can be mapped in software. This allows, for example, the modular development and commissioning of production cells. Documentation is also simplified and adaptations to additional customer requirements can be implemented quickly.
• The integrated, browser-based TwinCAT HMI visualization solution enables convenient development and maintenance of visualization objects. The information is presented either on the machines and systems or via the internet using a web browser.
• TwinCAT IoT provides the prerequisite for data aggregation in the cloud or locally in the production plant. TwinCAT also includes standardized communication protocols for cloud applications.
• The collected data can be specifically evaluated using TwinCAT Analytics.
• The TwinCAT interfaces to machine learning algorithms allow the use of AI methods in the traditional control environment.

TwinCAT Motion Control: perfectly suited for hydraulic and electric drive technology

Motion Control has been an important part of Beckhoff's software engineering tools for many years. With TwinCAT PTP and TwinCAT NC I, the requirements of electric drive technology in plastics machines and their peripherals are perfectly covered. A wide range of software modules for different tasks such as cam plates, synchronization and interpolating movements of several axes are available. NC PTP is perfectly suited for the widely used Cartesian removal systems; integration into the machine controller of the processing machine is easily feasible. The TwinCAT Plastic Application Components are available for stand-alone handling applications. As an industry-specific extension of the TwinCAT, they support the widely used Euromap interfaces between injection molding machine and robot, either as Euromap 67 or in the future as Euromap 79 (OPC 40079).

Fast removal processes, such as in-mold labeling with the help of side removal handling, are optimized with PC- and EtherCAT-based control technology: EtherCAT as a fieldbus with virtually delay-free synchronization leads to extremely short cycle times. Following the philosophy of open automation technology, TwinCAT Motion Control is a tool for the design of production cells that allows the integration of Beckhoff drive components as well as third-party components. TwinCAT NC-PTP is a suitable engineering tool for a variety of drive concepts: from simple switched axes and stepper motors or frequency converters to servo drives.

Different encoder technologies with fieldbus interfaces or direct connection via I/Os are supported. This makes it possible to design production cells modularly, flexibly and at an optimal cost according to market requirements. In particular, the linking possibilities of master and slave axes in almost any structure as well as the powerful and diverse motion functions of TwinCAT cover wide-ranging applications in outstanding fashion. With the Flying Saw software library, for example, trimming units in extrusion lines can be perfectly synchronized. Powerful tools such as the TwinCAT CAM Design Tool and the TwinCAT Scope support machine design and commissioning. PLC libraries with function blocks according to the PLCopen Motion Control standard facilitate programming and save engineering effort through the reusability of the modules.

Flexible and fully integrated robotic solution saves engineering effort

The TwinCAT Kinematic Transformation software integrates the robot controller into the automation software, so that PLC, motion control and robotics can run on one Industrial PC. In TwinCAT, a uniform engineering tool for configuration and programming is available to the user. This saves time and eliminates interface problems while at the same time reducing development costs. In addition to the Cartesian portal, serial 2D kinematics, 2D parallel kinematics and 3D delta kinematics, six-axis kinematics are also easy to implement. The respective kinematics can be selected and parameterized conveniently in the TwinCAT System Manager. The kinematic channel is used to parameterize the type (e.g., delta or SCARA) and the bar lengths and offsets. Mass and mass inertia values can be specified for dynamic pre-control. In addition, the software library also includes tracking functionalities. This means that the robot is synchronized with a moving object, so that it can pick up workpieces from conveyor belts or inclined turntables, for example.

The seamless integration of robot kinematics in the control system not only avoids the need for an additional robot CPU, it also ensures optimum interaction and synchronization with the PLC and the existing motion control functions: direct interfaces replace the complex communication between different controllers and systems. This results in high performance and improved accuracy.

TwinCAT Kinematic Transformation can be used with six-axis robots in plastics technology. As an industry-specific extension of the Beckhoff software platform, the TwinCAT Plastic Application Components support the widely used Euromap interfaces between injection molding machine and robot, either as Euromap 67 or in the future as Euromap 79 (OPC 40079).

OPC UA: the platform for all future standards in the plastics industry – essentially driven by Beckhoff

Beckhoff has been a staunch advocate of open standards for many years, from a time when proprietary solutions were still widely used. This also includes great commitment in the field of OPC standardization. Beckhoff customers therefore benefit from a particularly extensive interoperability between Beckhoff products and those of third parties.

Beckhoff is one of the few companies that has its products examined annually for real interoperability and stability in the latest versions and with the latest functions. Companion Specifications are currently being defined in the different domains of mechanical engineering. In plastics technology, this is being driven by the Euromap organization. Beckhoff is actively involved in the Companion Specifications for the plastics industry and can therefore promptly integrate new specifications into its products. Within TwinCAT, an OPC UA interface is optionally available (TF6100) that satisfies the corresponding Euromap Companion Specifications. The Euromap 82 (OPC 40082) has been implemented for machine-to-machine communication; the Euromap 77 (OPC 40077) is available for connection to master computers or to the cloud. In addition to the OPC UA-based Euromap interfaces, Beckhoff strongly recommends the use of EtherCAT as a deterministic fieldbus for time-critical processes such as robot synchronization in high-performance injection molding.