OPTO4L GmbH joins in the EtherCAT Technology Group
Why we have opted for EtherCAT
Our sensors for light, color, transmission and reflectivity are used in applications focusing on very short cycle times. At the same time, it is in the nature of light and color measurement that the volume of data produced is significantly larger than usually generated with other sensors for a specific analog measured variable. This is particularly true for measuring instruments based on spectroscopic techniques or – as quite common in 100% final testing in series production of automotive products – when color and intensity of more than 100 LEDs need to be precisely captured and evaluated in a single test cycle. Today, modern production processes very rarely use data that has been pre-processed by the sensor itself, e.g. traditional teach-in sensors mostly producing a binary result. That is because it contravenes requirements such as traceability and predictive maintenance. Moreover, it almost makes it impossible to have dynamic production processes with changing type varieties and products.
In our search for the most suitable fieldbus, closely matching our instruments and the potential applications, we came across EtherCAT early on. The exceptionally short cycle time and the very large process data blocks convinced us from the start. In the future, the capability to capture the overall status of a process across device boundaries and down to the nanosecond will enable HiL (Hardware in the Loop) applications for light and color information obtained in tests and simulations in the automotive and aerospace sector. Until now, this required extensive auxiliary equipment such as high-end multichannel data loggers and the use of, e.g. “analog options”, of otherwise digitized LED testing instruments.
Will all these possibilities not require very complex hardware design? Will the effort required for the implementation but also for testing and commissioning of such sensors in production not be disproportionately high? The answer is “No!” The rapid dissemination of EtherCAT technology and increasing availability of compact slave implementations in single chips and SoCs, in our view, reduces implementation time and cost in comparison to other fieldbuses. The EtherCAT Technology Group supports the development on all levels, also with software and plug fests, thus ensuring conformity and above all, interoperability. Since nearly all components responsible for operational safety of EtherCAT (from slave perspective) are hardware-implemented, the development risk for new devices is significantly lower than with other fieldbus systems.
What about the end user? Will he be required to have extensive specialist knowledge to create and maintain EtherCAT systems? The answer is “No!” From user perspective, EtherCAT retains the huge advantage all modern fieldbus systems provide: the slaves already deliver all the information needed for interpreting the process data exchanged! Moreover, the fact that standard Ethernet connections and non-expensive plug-in boards are sufficient on master side for creating a reliable EtherCAT system so that the entire architecture equals a standard Ethernet network from system perspective, makes commissioning and realization of an EtherCAT system easier and more reliable than with other fieldbuses.
Ultimately, our reason to opt for EtherCAT was the firmly implemented EoE (Ethernet-over-EtherCAT) capability. For this purpose, free resources in EtherCAT transmission are used for additional transmission of standard Ethernet TCP/IP data, enabling the use of standard internet browsers on master side to address suitable slaves without interrupting ongoing EtherCAT communication. This way, EtherCAT seamlessly integrates into the overall concept of our future instruments and into the IoT (Internet of Things).
As a member of the fast growing EtherCAT Technology Group, we will continue to expand our expertise and know-how. Already in 2017, we will be presenting the first implementations in high-end LED testers and color sensors!