Optical Ethernet Backplane Using Passive PON for Deterministic I/O

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Solution Overview

Problem

Existing industrial control systems face challenges in achieving efficient and reliable high-speed communication between I/O modules and cluster managers, especially in scenarios with space constraints and a large number of I/O modules, where external switches become cumbersome and costly, and fail to meet real-time communication requirements.

Innovation Solution

The implementation of a passive optical network using a passive optical splitter and coupler for multipoint Ethernet connections, synchronized with Time Sensitive Networking switches and Precision Time Protocol, allowing for deterministic and high-performance data transmission without the need for external switches, using passive base plates and optical connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If external switches are used to connect I/O modules to cluster manager, then communication reliability is improved, but device complexity and cost increase

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

Solution Approach 1:

The patent extracts the active switching function from the backplane infrastructure and relocates it to the I/O modules themselves. Each I/O module is equipped with a port that can directly connect to the cluster manager, eliminating the need for external switches in the backplane. This extraction of the active component from the central infrastructure resolves the contradiction by maintaining communication reliability through direct connections while reducing overall device complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The I/O modules are designed to be self-sufficient with built-in communication capabilities. Each module has its own port and can independently communicate with the cluster manager without requiring external switching infrastructure. This self-service approach allows modules to maintain reliable communication while eliminating the complexity of external switches, as each module manages its own connection.

Inventive Principle:
Principle #25Self-service

2Speed

If external switches are used to support high number of I/O modules, then communication speed is improved, but cost and space requirements increase

Engineering Contradiction:
Improvecommunication speedVSAvoidcost
Core Design Contradiction:
SpeedVSEase of manufacture

Solution Approach 1:

The patent segments the communication infrastructure by providing each I/O module with its own dedicated port for connecting to the cluster manager. This segmentation eliminates the need for a centralized external switch that would require handling multiple high-speed connections. Each module maintains full-duplex communication capability independently, preserving communication speed while reducing the overall system cost by eliminating expensive external switching equipment.

Inventive Principle:
Principle #1Segmentation

3Reliability

If external switches are used for real-time communication, then data transmission reliability is improved, but response time increases

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidresponse time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts the communication path from the external switch infrastructure and creates a direct connection between I/O modules and the cluster manager. This extraction eliminates the additional response time introduced by external switching while maintaining data transmission reliability through the dedicated point-to-point connection. The direct connection reduces the number of hops and potential failure points in the communication path.

Inventive Principle:
Principle #2Taking out (Extraction)

4Device complexity

If passive optical network is used for multipoint connection, then device complexity is reduced, but communication reliability may be compromised

Engineering Contradiction:
Improvedevice complexityVSAvoidcommunication reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent uses optical splitters as passive intermediaries to enable multipoint connections without requiring active switching infrastructure. The optical splitter distributes optical signals from the cluster manager to multiple I/O modules and collects return signals. This intermediary approach maintains communication reliability by providing dedicated optical paths while reducing device complexity by eliminating the need for external active switches, as the passive splitter requires no power or active control.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution provides reliable, high-speed communication that respects real-time constraints, reduces costs, and minimizes the risk of failure by eliminating active components in the backplane, enabling full duplex communication at 1000 Mb/s or more with deterministic latency for I/O data and best effort service data transmission.

Implementation Method 1

the passive optical network includes a passive optical splitter for transmitting data from the cluster manager to the communication devices

Methodology Applied
Scientific EffectOptical splitting: Optical Fibre

Implementation Method 2

the passive optical network includes a passive optical coupler for transmitting data from the communication devices to the cluster manager

Methodology Applied
Scientific EffectOptical coupling: Optical Fibre

Data Source

PatentEP4451622A1Optical ethernet bus
Publication Date: 2024.10.23 SCHNEIDER ELECTRIC IND SAS
  • EP4451622A1 patent drawingFigure 1
  • EP4451622A1 patent drawingFigure 2
  • EP4451622A1 patent drawing

AI summary

The invention relates to an industrial system for controlling backplane communication, comprising: An industrial system for controlling backplane communication, comprising: a cluster manager (CM) linked to a set of communication devices including at least one Input/Output module (IOM) via a passive optical network (PON), wherein the passive optical network (PON) includes a passive optical splitter (POS) for transmitting data from the cluster manager to the communication devices, wherein the passive optical network (PON) includes a passive optical coupler (POC) for transmitting data from the communication devices to the cluster manager, wherein the communication devices are synchronized in time with the cluster manager and configured to send data via the passive optical network (PON) at respective scheduled time windows.