Master-Slave Safety Controller Network Aggregation

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Solution Overview

Problem

In large groups of safety controllers, the complexity of data transmission limits the number of possible participants in a network, as the number of logical communication connections and data packets exceeds what can be processed within a predetermined time, making secure data exchange challenging.

Innovation Solution

A master device is introduced to collect data packets from multiple slave safety controllers, forming a collective data packet that is sent to all slaves, reducing protocol overhead and interrupt load, and allowing for scalable communication without direct slave-to-slave communication, with features like data processing, electronic signatures, and configurable timing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If each safety controller communicates directly with every other controller in the network, then complete data exchange between all participants is achieved, but the number of logical communication connections and data packets exceeds processing capacity within predetermined time

Engineering Contradiction:
Improvenumber of network participantsVSAvoidnumber of logical communication connections
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces a master controller as an intermediary that receives data packets from all slave controllers, aggregates them into collective data packets, and distributes them to all slaves. This mediator approach reduces the communication complexity from O(N^2) direct connections to O(N) connections through the master, enabling scalable network expansion while maintaining complete data exchange capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The master controller merges multiple individual data packets from different slave controllers into single collective data packets. By combining data transmissions, the system reduces the total number of data packets that need to be processed individually, decreasing interrupt load and allowing the network to support more participants within the processing time constraints.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If multiple individual data packets are transmitted between safety controllers, then complete data exchange is achieved, but protocol overhead and cumulative switchover time increase

Engineering Contradiction:
Improvedata exchange completenessVSAvoidcumulative switchover time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The master controller combines multiple individual data packets into single collective data packets before distribution. This merging reduces the total number of transmission events and associated protocol overhead, thereby decreasing the cumulative switchover time while ensuring all necessary data is exchanged complete and accurately.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If each data packet is processed individually by safety controllers, then data accuracy is maintained, but interrupt load exceeds acceptable levels

Engineering Contradiction:
Improvedata processing accuracyVSAvoidinterrupt load
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system merges multiple individual data packet processing operations into single collective data packet processing at the slave level. By receiving and processing aggregated data packets rather than handling numerous small packets individually, the interrupt load is significantly reduced while the processing accuracy is maintained through the structured aggregation and distribution mechanism managed by the master controller.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3435179B1Method for functionally secure exchange of information according to a safety standard
Publication Date: 2020.07.08 WIELAND ELECTRIC GMBH
  • EP3435179B1 patent drawingFigure 1~2
  • EP3435179B1 patent drawingFigure 3~4
  • EP3435179B1 patent drawingFigure 5

AI summary

A method for the functionally safe exchange of information between at least three safety controllers, configured to control an electrical load in a functionally safe manner according to a safety standard, is intended to allow the interconnection of a comparatively large number of safety controllers in a network while simultaneously ensuring secure communication. For this purpose, a master (M1) is provided, and a plurality of safety controllers are configured as slaves (S1...SN). Data packets (DS1...DSN) are received by the master (M1) from a plurality of slaves (S1...SN), the master (M1) combines the data packets (DS1...DSN) into a single data packet (DM1), and sends the single data packet (DM1) to all slaves (S1...SN).