September 2021

SWITCHING INTO SAFETY ENGINEERING n of operation mode on a touch panel without additional mechanical controls. The procedure was approved by the Institute for Occupational Safety and Health of the German Social Accident Insurance (Institut für Arbeitsschutz, IFA). This Institute confirms that selection of operation mode with a touchscreen is possible up to PL e according to EN ISO 13849-1. This requires using the EKS FSA in combination with suitable software in the failsafe PLC. The procedure also allows so-called softkeys to be used instead of a touchscreen, also up to PL e. Industry 4.0 and Smart Machines As manufacturers are continuing to enter the age of Industry 4.0, the requirements for information transparency and machine interconnectivity is ever increasing. Intelligent monitoring capabilities make it possible for an operations manager to see the status of a production facility at any moment in time, or the equipment manufacturer to receive condition updates to replenish consumables automatically. Safety interlocks and guard locking devices are now capable of transmitting key information. Process data is sent to the control system, including status signals, such as the position of the door or guard locking, indication of whether a switch is out of alignment. Moreover, other services can be used to collect data such as the switch temperature, the applied voltage and number of operating cycles. With these advances, it is now very easy for a factory maintenance team to key into a machine’s maintenance programme and schedule maintenance and repair and from an external position, and for the machine manufacturer to remotely monitor the safety aspects of the machine, its guards and other safety elements. This results in positive accounting rather than disaster management, optimising plant uptime and reducing unwanted costs. Collaborative robot safety Increasingly forming part of the production environment, collaborative robots (cobots) share tasks with humans. Integrated safety features allow them to work with or close by humans. Despite these, safe implementation based on comprehensive risk assessments is crucial. The area in which a collaborative robot operates, including any tooling or additional equipment, is known as the collaborative workspace, the space within the safeguarded area where the robot and human can perform tasks simultaneously during production operations. It is extremely important to review the entire area for any circumstances where an operator could be trapped or clamped by the robot and surrounding pieces of equipment. The safety standard ISO 10218 and technical specification RIA TS 15066 define the safety functions and performance of a collaborative robot. Safety devices are generally quite easy to integrate into a collaborative robotic application. These include: n Open area safety guarding (eg safety area scanners and mats). n Gated/limited area safety guarding solutions (eg light curtains and safety switches) n Active hazards safety guarding (eg a “deadman” switch that automatically goes back to the “off” position if the user fails to exert pressure. n References • Euchner Safety Book, pp85-102 • https://www.euchner.de/en-us/service/eks- application-examples/ • https://assets.euchner.de/uploads/127382_07- 07-18_Flyer-EKS-Betriebsartenwahl.en-us.pdf This is the fifth part of our ‘Switching into safety engineering’ series which will include comprehensive articles and follow-up Zoom Q&A sessions – to register for the series or to request a copy of the free machinery safety guidebook, please visit www.drivesncontrols.com * This article (and the previous four articles) - is also available on our website: https://drivesncontrols.com/news/fullstory.php/aid/6671/Safety_Engineering.html There, you will also be able to register for the accompanying Q & A Zoom sessions. TYPES OF BUS SYSTEMS Bus System Failsafe Protocol PROFIBUS AND PROFINET PROFIsafe EtherCAT FSoE (Functional Safety over EtherCAT) ASi SaW (Safety at Work) DeviceNet, Ethernet/IP, Sercos CIP Safety CC-Link CC-Link Safety CC-Link IE CC-Link Safety (possibly PROFIsafe) Powerlink Open Safety See Euchner Safety Book pp86-90 for further information Table 1: Types of bus systems Are wireless systems safe? Wireless communication is often proposed as a key enabling technology for the implementation of advanced manufacturing systems. Factory operators could control operations in ways that are cost-prohibitive with wires. However, there are technical challenges, including time synchronisation, reliability, latency determinism, resilience to interference from factory-generated noise and other transmission security vulnerabilities. Over time, it is expected that new protocols for future automation systems will address these challenges.