Methods and apparatuses for monitoring the functionality of redundantly interconnected contacts

Abstract

For providing a very simple and reliable monitoring of the functionality of contacts together with a high flexibility of selection of the contacts a method for monitoring the functionality of redundantly interconnected contacts is provided, preferably within a load current circuit, wherein said n contacts, n = 2, provide an electrical connection between a power supply and a load, wherein said n contacts are switchable by a controller and wherein each of said n contacts is designed for providing the electrical connection between the power supply and the load all alone. The method is characterized in that the controller switches on said n contacts during n subsequent activations according to a defined schedule according to which at the first of said n subsequent activations one of said n contacts is switched on first and the remaining n-1 contacts are switched on afterwards, so that a verification regarding the functionality of said one of said n contacts is possible, and according to which at each of the n-1 remaining subsequent activations a further one of said n contacts is switched on first with switching on of the remaining n-1 contacts afterwards, so that after said n subsequent activations each of said n contacts has once been switched on first and a verification regarding the functionality of each of said n contacts is possible. Further, a corresponding method for subsequent deactivations and corresponding apparatuses are provided.

Description

technical field [0001] The present invention relates to a method for monitoring the function of redundant interconnection contacts, preferably used in load current circuits, wherein said n (n=2,...,) contacts provide a connection between power supply and load wherein the n contacts can be switched by the controller, and wherein each of the n contacts is designed to individually provide an electrical connection between the power source and the load. Furthermore, the invention relates to a corresponding device for monitoring the function of redundant interconnection contacts. [0002] In general, the invention relates to the field of safety-related systems or safety-related communication systems in which, for example, reliable switching on and / or switching off of functions or loads is necessary. Background technique [0003] From US 2012 / 0229938 A1 a method and a device are known for monitoring the function of redundant interconnection contacts. This document shows a safety-...

AI Technical Summary

Problems solved by technology

However, this leads to significant limitations regarding the selection of relays or contacts in a single application to the positively driven contacts or relays

[0007] Minimizing risk through redundancy has the disadvantage that failures based on the same cause (i.e. common cause) are still potentially dangerous to the load or function to be protected

Adding redundancy can provide a slight improvement in safety, however, due to limited installation space, adding redundancy is not always possible

[0008] The use of positively driven contacts or relays generally provides an improvement, however, the implementation of positively driven contacts or relays requires an enlarged installation space and limits the selection possibilities regarding the components of the device

[0009] Known methods and devices for monitoring the function of redundant interconnect contacts require complex circuits and often large installation spaces to provide a high level of risk minimization

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