RS-485 Full-Duplex via Inverted Master-Slave Architecture

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Solution Overview

Problem

The RS-485 interface in electronic devices experiences low communications speed and delay due to its polling scheme, and transitioning to full-duplex communications is hindered by data collisions and the need for costly replacements of existing transmission lines and devices.

Innovation Solution

Electronic devices operate without a designated master or slave configuration, allowing simultaneous data transmission and reception by generating both transmission and reception enable signals, enabling full-duplex communications and easy collision detection, while minimizing the need for hardware modifications and costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If polling scheme is used in RS-485 interface, then device control and data transmission can be achieved, but communications speed is slow and delays occur

Engineering Contradiction:
Improvecommunications speedVSAvoidcommunication delay
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent inverts the traditional master-slave polling architecture by allowing all devices to transmit data immediately without waiting for master device permission. Each device operates as an equal participant that can initiate transmissions at any time, fundamentally reversing the permission-based communication flow of conventional RS-485 systems.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent implements preliminary collision detection mechanisms where devices check transmission line status before sending data and continuously monitor during transmission. This proactive approach prevents data collisions before they occur, allowing devices to maintain high-speed continuous transmission without waiting for master device polling cycles.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If full-duplex communications is implemented in RS-485 interface, then simultaneous data transmission and reception is enabled, but data collisions occur and costly hardware replacements are required

Engineering Contradiction:
Improvesimultaneous transmission and receptionVSAvoiddata collision
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent implements continuous feedback mechanisms where each device monitors the transmission line for collision signals during data transmission. When a collision is detected through feedback from the transmission line status, devices immediately halt transmission and implement backoff protocols, enabling full-duplex operation without the harmful collision effects.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces an intermediary collision detection and arbitration mechanism that mediates between multiple devices attempting simultaneous transmission. This intermediary system detects collisions and coordinates transmission rights, allowing full-duplex communications to proceed without data corruption from unmanaged collisions.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If full-duplex communications is implemented in RS-485 interface, then communication efficiency is improved, but expensive hardware replacements and long implementation time are required

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidhardware replacement cost
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent creates a virtual full-duplex communication layer that copies the functionality of dedicated full-duplex hardware through software-based collision detection and arbitration mechanisms. This virtual implementation layer runs on top of existing half-duplex RS-485 hardware, providing full-duplex communication efficiency without requiring expensive physical hardware replacements.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent changes the operational parameters of existing RS-485 hardware by modifying transmission control logic and timing parameters through software. By adjusting these parameters, the system achieves full-duplex communication efficiency using the existing hardware infrastructure, avoiding the need for expensive hardware modifications or replacements.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3285437B1Electronic device and communications method thereof
Publication Date: 2019.10.02 LG ELECTRONICS INC
  • EP3285437B1 patent drawingFigure 1
  • EP3285437B1 patent drawingFigure 2
  • EP3285437B1 patent drawingFigure 3

AI summary

Disclosed herein are an electronic device that conducts communications via an RS-485 interface, and a communications method for electronic devices. In order to address low communications speed and communications delay resulted from polling employed by existing RS-485 interfaces, electronic devices are not designated as a master device and slave devices. Accordingly, all of the electronic devices behave like existing master devices. Each of the electronic devices transmits data to another electronic device whenever it wants without permission of another device.