Single-Wire Safety Control Interface for Fault and Alarm Detection

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Solution Overview

Problem

Existing safety control systems face challenges with remote intelligent sensing devices (ISDs) due to susceptibility to electromagnetic interference (EMI), complex bidirectional data communication requirements, and increased complexity and cost from multiple wired connections, which complicates fault detection and mitigation in flammable and/or toxic refrigerant systems.

Innovation Solution

A multi-functional single wire interface for ISDs in safety control systems, which provides voltage level indication of alarm and fault conditions, embedded bidirectional serial communication for transmitting sensed data, and the ability to detect disconnected or mis-wired sensors and open or shorted signal wires, allowing for robust and reliable communication using a single wire.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple wired connections are used for ISD communication, then bidirectional data communication capability is improved, but device complexity and susceptibility to EMI increase

Engineering Contradiction:

Improvebidirectional data communication capabilityVSAvoidnumber of wired connections

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines power supply and data communication functions into a single wire interface. The single wire carries both power to the ISD and bidirectional digital data signals, eliminating the need for separate power and data cables. This merging reduces the number of connections while maintaining full communication capability and power supply.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single wire interface is designed to perform multiple functions simultaneously: it provides power supply to the ISD, transmits data bidirectionally between the control circuit and ISD, and enables fault detection. This multi-functional approach replaces traditional separate cables for power and data, reducing system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If complex bidirectional communication interfaces are implemented, then data communication capability is improved, but fault detection capability deteriorates

Engineering Contradiction:

Improvedata communication capabilityVSAvoidfault detection capability

Core Design Contradiction:

Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The single wire interface incorporates feedback mechanisms that allow the control circuit to monitor the electrical state of the wire continuously. By analyzing voltage levels, current flow, and signal characteristics on the single wire, the system can detect faults such as wire breaks, short circuits, or ISD failures while maintaining bidirectional communication capability.

Inventive Principle:

Principle #23Feedback

3Reliability

If multiple wired connections are used for ISD communication, then communication reliability is improved, but ease of manufacture deteriorates

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidinstallation complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges power supply and data communication into a single wire connection, dramatically simplifying installation. Instead of requiring technicians to connect multiple separate cables for power and data, the single wire interface requires only one connection point at the ISD, reducing installation time and potential wiring errors while maintaining communication reliability.

Inventive Principle:

Principle #5Merging (Combining)

4Device complexity

If traditional power-line communication systems are used, then wiring complexity is reduced, but adaptability to different standards deteriorates

Engineering Contradiction:

Improvewiring complexityVSAvoidcompatibility with communication standards

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The single wire interface is designed as a universal solution that can work with various ISD types and communication protocols. The interface circuitry can be configured to support different data formats and communication modes while maintaining the same physical single-wire connection, providing both wiring simplicity and standard adaptability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12332642B2Fault tolerant interface for safety controls

Publication Date: 2025.06.17 PARKER HANNIFIN CORP

AI summary

A fault tolerant interface includes a sensor and a safety control that are electrically connected to each other by a single wire. The sensor is configured to provide various signals to the safety control dependent on environmental parameters. Based on the ignal received by the safety control, the fault tolerant interface may act accordingly and place the overall system in a mitigative state in the event of a fault state or an alarm state. Data and fault or alarm states are detected by determining a first time interval between a first edge and a second edge of a signal, wherein an edge is one of a transition of the signal from a first voltage to a second voltage or a transition of the signal from the second voltage to the first voltage on a single wire. Data values versus fault or alarm states are assigned based on whether a current time interval corresponds to the first time interval or the second time interval, or another time interval associated with alarm or fault states.