I/O Module Primary Central Unit Selection via Fieldbus States

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Solution Overview

Problem

Current systems for detecting failures in industrial programmable logic controllers rely heavily on communication between central units, which can lead to prolonged detection times and require specific central units and software, increasing costs and complexity.

Innovation Solution

An input/output module with processing means that communicates with both central units via separate field buses, allowing for the selection of a primary central unit based on bus and unit operating states, prioritizing consistent information, and enabling fallback solutions to reduce reaction time and redundancy checks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two central units are permanently in communication to ensure redundancy, then system reliability is improved, but detection time increases and specific central units with dedicated software are required

Engineering Contradiction:
Improvesystem reliabilityVSAvoiddetection time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent divides the redundancy function into two independent parts: a first central unit with a first processor and a second central unit with a second processor. Each processor independently executes the same application program and communicates with input/output modules via separate field buses, eliminating the need for permanent communication between central units while maintaining reliability through independent operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces field buses as intermediary communication channels between central units and input/output modules. Each central unit communicates independently through its own field bus, allowing parallel operation without direct communication between central units, thus reducing detection time while maintaining system reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If two central units are permanently in communication to ensure redundancy, then system reliability is improved, but device complexity increases due to dedicated software requirements

Engineering Contradiction:
Improvesystem reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes each central unit universally capable by equipping both the first and second processors with identical communication interfaces and the ability to execute the same application program. This universality allows either unit to independently control the system without requiring specialized dedicated software, reducing device complexity while maintaining reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent changes the operational parameters of the central units by allowing them to operate independently with the same configuration and software. Instead of requiring one unit to be master and the other slave with dedicated communication protocols, both units operate with equal parameters, simplifying the system architecture.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If information exchange between central units and input/output modules follows cycles based on central unit clock frequency, then system coordination is maintained, but detection time increases

Engineering Contradiction:
Improvesystem coordinationVSAvoiddetection time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The patent implements preliminary action by having each central unit independently and continuously execute the application program and monitor system state before any failure occurs. This continuous independent monitoring allows immediate detection of failures without waiting for scheduled communication cycles between central units.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent ensures continuity of useful action by having both central units continuously execute the application program and communicate with input/output modules independently through their respective field buses. This continuous independent operation maintains system coordination while enabling faster failure detection compared to periodic inter-unit communication.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP2251789B1Input/output module for sensors and/or actuators exchanging information with two central processing units
Publication Date: 2011.11.02 ABB AG(DE)
  • EP2251789B1 patent drawingFigure 1
  • EP2251789B1 patent drawingFigure 2

AI summary

The module (6) has communication units communicating with central units (2a, 2b) by fieldbuses (5a, 5b), respectively. A processing unit i.e. microprocessor, establishes selection of a primary central unit from the central units by taking into account a functioning state of each fieldbus, a functioning state of each central unit and consultation of information provided by the central units. The processing unit controls outputs of the module according to information received from the primary central unit. An independent claim is also included for a modular programmable industrial automaton comprising a sensor and/or an actuator.