CAN XL Node Monitoring via Voltage Phase Detection

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Solution Overview

Problem

Existing CAN monitoring devices cannot detect CAN XL data phases and switch transceiver modes, making them unable to monitor CAN XL nodes and perform diagnostic functions on CAN XL networks, as they lack the capability to differentiate between positive and negative differential bus voltages used in CAN XL transceivers.

Innovation Solution

A monitoring device that detects unique sequences of zero, negative, and positive voltages in CAN XL data frames to switch transceiver modes, allowing it to route dominant data or logic 0/1 between CAN XL nodes, without requiring complex CAN XL protocol controllers, and supports various frame lengths, including those beyond the current CAN XL specifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If CAN Classic/CAN FD transceivers are used, then compatibility with existing CAN networks is maintained, but the ability to monitor CAN XL nodes with symmetric differential mode transmission is lost

Engineering Contradiction:

Improvecompatibility with existing CAN networksVSAvoidability to monitor CAN XL nodes

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The monitoring device dynamically switches its transceiver between asymmetric differential mode (for CAN Classic/CAN FD compatibility) and symmetric differential mode (for CAN XL monitoring). This dynamic mode switching enables the device to adapt to different CAN protocols and monitor CAN XL nodes effectively, resolving the contradiction between maintaining compatibility and achieving reliable monitoring.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The device changes its operational parameters by switching between different differential modes (asymmetric vs. symmetric) depending on the required communication protocol. This parameter change allows a single monitoring device to handle both legacy CAN networks and modern CAN XL networks, maintaining both compatibility and monitoring capability.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If CAN XL transceivers operate in symmetric differential mode, then data transmission capability is improved, but the ability of legacy transceivers to differentiate between positive and negative differential voltages is lost

Engineering Contradiction:

Improvedata transmission capabilityVSAvoidvoltage differentiation capability

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The monitoring device dynamically adjusts its transceiver mode based on the communication requirements. When monitoring CAN XL nodes in symmetric differential mode, the device switches to symmetric mode to accurately differentiate between positive and negative voltages representing logic 0/1. This dynamic adaptation maintains high data transmission capability while preserving voltage differentiation precision.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If mode switching logic is added to CAN XL transceivers, then transceiver functionality is improved, but device complexity increases

Engineering Contradiction:

Improvetransceiver functionalityVSAvoidmode switching logic

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Instead of embedding complex mode switching logic within each CAN XL transceiver, the patent introduces a separate mode router as an intermediary component. This mode router receives mode switch requests from transceivers and coordinates the mode switching across multiple transceivers, centralizing the complexity in a dedicated component rather than distributing it throughout the system.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The monitoring device creates a simplified copy of the mode switching functionality that can be implemented without requiring complex CAN XL protocol controllers. By using voltage change detection and defined voltage change criteria, the system achieves mode switching capability with reduced complexity compared to full protocol controller implementation.

Inventive Principle:

Principle #26Copying

4Ease of operation

If CAN XL protocol controllers are used for mode switching, then transceiver control is improved, but system cost increases

Engineering Contradiction:

Improvetransceiver controlVSAvoidsystem cost

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

The patent creates a simplified copy of the mode switching control functionality that does not require expensive CAN XL protocol controllers. By using voltage change detection and comparing voltages against predefined thresholds, the system achieves effective transceiver control at lower cost.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

Instead of using expensive, complex CAN XL protocol controllers, the invention employs simpler, more cost-effective voltage detection circuits and comparison logic. These simpler components achieve the same functional outcome (mode switching control) at reduced cost, making the system more economical while maintaining ease of operation.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Data Source

PatentUS11804977B2Monitoring controller area network (CAN) XL nodes

Publication Date: 2023.10.31 VOLVO CAR CORP

AI summary

A method can comprise determining, by a device comprising a processor, a transition between an arbitration phase of a Controller Area Network (CAN) XL node of a group of communicatively coupled CAN XL nodes of a CAN bus network and a data phase of the CAN XL node based on a voltage change of a voltage level of the CAN XL node being determined, by device, to satisfy a defined voltage change criterion of defined voltage criteria, wherein the data phase comprises both positive voltages and negative voltages, and in response to determining the transition, routing, by the device, dominant data or logic 0/1 data of the CAN XL nodes to other nodes of the group of CAN XL nodes.