Shared Digital I/O Isolation for Compact Safety Logic Control
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Solution Overview
Problem
Existing electric logic control devices face challenges in providing a flexible and compact input/output facility arrangement, especially in small frequency converters where additional safety-related functionality requires increased space due to the need for additional I/O cable connectors.
Innovation Solution
The proposed input/output facility arrangement integrates both safety-related and non-safety-related digital input/output connections with isolation, allowing for a shared digital input/output connection that separates safety and non-safety logic controller modules, thereby reducing physical space requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate safety-related and non-safety-related input/output facilities are implemented, then functional safety requirements are met, but device space and complexity increase
Solution Approach 1:
The patent combines safety-related and non-safety-related digital input/output connections into a single shared physical I/O facility. The isolation unit separates the signal paths logically while allowing both types of connections to coexist in the same physical interface, reducing the number of separate connectors needed.
Solution Approach 2:
An isolation unit is introduced as an intermediary component between the shared digital input/output connection and the controller modules. This isolation unit enables safe signal separation without requiring physically separate I/O facilities, thus meeting safety requirements while sharing the same physical interface.
2Reliability
If additional safety-related functionality is added to small frequency converters, then functional safety is improved, but space requirements increase due to additional I/O cable connectors
Solution Approach 1:
The shared digital input/output connection is designed to serve multiple functions - both safety-related and non-safety-related operations. This multi-functional interface eliminates the need for separate dedicated connectors for safety functions, saving space in compact frequency converters.
Solution Approach 2:
Safety-related and non-safety-related I/O connections are merged into a single physical interface structure. This consolidation allows small frequency converters to accommodate safety functionality without increasing the number of external cable connectors or occupying additional space.
3Reliability
If fully separated safety-related and non-safety-related input/output connections are used, then signal interference is prevented, but flexibility and space efficiency are reduced
Solution Approach 1:
The isolation unit acts as a mediator that maintains signal separation while allowing flexible configuration. It enables the system to switch between safety-related and non-safety-related modes using the same physical interface, providing adaptability without compromising signal integrity.
Data Source
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AI summary
The invention relates to the field of electric logic control devices and electric machines, such as electric motors and electric generators for industrial applications, and more particularly to an input/output facility arrangement in an electric logic control device and to an electric logic control device. The an input/output facility arrangement (20, 30, 40, 50, 60, 70, 100) in an electric logic control device, said arrangement comprising a digital input/output connection (11, 41, 51) arranged both for safety related input/output and for non-safety related input/output, a non-safety logic controller module (13) and a safety logic controller module (12) or a safety logic interface (61), wherein said safety logic controller module (12) or said optional safety logic controller module (62) is configured to communicate signalling to/from said digital input/output connection (11, 41, 51), and said digital input/output connection (11, 41, 51) comprises an isolation between said non-safety logic controller module (13) and said safety logic controller module (12) or said optional safety logic controller module (62).