IEC IEC TS 60601-4-6 Edition 1.02024-04 TECHNICAL SPECIFICATION olour inside INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 11.040.01; 33.100.20 ISBN 978-2-8322-8809-2 Warning! Make sure that you obtained this publication from an authorized distributor. ? Registered trademark of the International Electrotechnical Commission - 2 - IECTS60601-4-6:2024@IEC2024 FOREWORD INTRODUCTION.. Scope. 1 .8 2 Normative references .. 8 3 Terms, definitions and abbreviated terms 3.1 Terms and definitions. 3.2 Abbreviated terms... 4 How to use this document. 5 General 10 5.1 Mitigation of effects caused by EM DISTURBANCES . .10 5.2 Implementing well-proven techniques and measures for mitigating the effects that can be caused by EM DISTURBANCES... 5.2.1 General principles .. 5.2.2 Choosing design techniques and measures from Annex A. 5.3 Documenting the well-proven techniques and measures used for mitigating the effects that can be caused by EM DISTURBANCES .13 5.3.1 ME EQUIPMENT Or ME SYSTEM.. .13 5.3.2 Non-ME EQUIPMENT..... Annex A (informative) Detailed guidance on the techniques and measures for mitigating the effects that can be caused by EM DISTURBANcES.. 15 A.1 Techniques and measures that might be helpful in project management, planning and specification.. .15 A.1.1 Techniques and measures for project management and planning ... ....15 A.1.2 Techniques and measures for use when creating a design specification ...... 15 A.1.3 Specifying EMC test standards to help ensure availability. .16 A.1.4 Protecting against high impact, unusual and malicious EM DISTURBANCEs..... 19 A.2 A.2.1 General ... .20 A.2.2 Separating system parts necessary for achieving BAsic SAFETY or ESSENTIAL PERFORMANCE from system parts that are not important for BASIC SAFETY OrESSENTIAL PERFORMANCE.. 20 A.2.3 Recording how the design specifications are achieved through design choices.... .21 A.2.4 Co-design electromagnetically diverse hardware/software in redundant channels....... .21 A.2.5 System integration, installation, and commissioning ... A.2.6 Fault detection and event data recording for later diagnosis ... A.2.7 Improving mitigation of the effects that can be caused by EM DISTURBANCEs in communication links... ...26 A.2.8 Synchronizationandresynchronizationtechniques.... ...28 A.2.9 Protection from persistent interference by monitoring retry counts ... ....28 A.2.10 IndependentdetectionofEMDIsTURBANcEsand/orEMl. A.2.11 Protection of systems from tampering via communication links to external systems .... ....30 A.2.12 Robust, high-specification electromagnetic mitigation .. ..31 A.2.13 Techniques and measures to prevent Risks being increased by virtualization of memory and PRocEss resources (e.g. a "digital twin").... ........31 A.2.14 Usability Engineering (Human Factors)... A.3 Techniques and measures that might be helpful in operational design ....... IEC TS 60601-4-6:2024 @IEC 2024 - 3 - A.3.1 General , .32 A.3.2 Developing appropriate operation and maintenance instructions... ..33 A.3.3 Designing appropriate maintenance techniques ... ....33 A.3.4 Limiting the possibilities for operation and hence mis-operation....... ....34 A.3.5 Protecting against operation errors ... A.3.6 Protecting against hardware or software modifications or manipulations ......35 A.3.7 Defensive programming techniques ... ...35 A.3.8 Limited use of interrupts ........ ...38 A.3.9 Limited use of memory address pointer variables .... ..39 A.3.10 Avoiding recursion.......... A.3.11 Error detection and correction for invariable memory....... A.3.12 Error detection and correction techniques in redundant designs .. A.3.13 Time-based error detection/correction in buses and interfaces ... ....42 A.3.14 Error detection and correction for variable memory.. A.3.15 Error detecting/correcting coding for ROM, RAM, buses, and interfaces ......45 A.3.16 Error detection and correction for logic and data processing.. ..45 A.3.17 Error detection and correction for electrical and electromechanical compo