Fire System Degraded Mode for Communication Reliability

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Solution Overview

Problem

Existing fire systems relying on master-slave communication networks fail to trigger alarms properly in emergency situations due to faults in the communication system, leading to potential safety issues as remote units are reliant on the fire panel for communication and power.

Innovation Solution

The fire system incorporates a degraded mode of operation where remote units can communicate with each other using current sensors to detect modulations in the loop, allowing them to trigger alarms independently of the fire panel, even if master-slave communications fail, and are powered independently to ensure continuous operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If master-slave communication system is used for fire panel and remote units, then compatibility with previously installed products is ensured, but system reliability deteriorates when communication faults occur

Engineering Contradiction:
Improvecompatibility with previously installed productsVSAvoidsystem reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system is segmented into two independent communication modes: master-slave communication for normal operation and peer-to-peer communication for degraded mode. This segmentation allows the system to maintain compatibility with existing products while establishing an independent failure path that does not rely on the fire panel, thereby resolving the contradiction between adaptability and reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The communication protocol parameters are changed based on system state. In normal mode, the system uses master-slave communication with the fire panel as master. When communication faults are detected, the system transitions to degraded mode where remote units change their communication parameters to enable direct peer-to-peer signaling, allowing alarm information to propagate independently of the fire panel.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If remote units rely on fire panel for communication and power, then system complexity is reduced, but system reliability deteriorates when fire panel fails

Engineering Contradiction:
Improvesystem complexityVSAvoidsystem reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system performs preliminary action by establishing peer-to-peer communication capabilities in advance during normal operation. Remote units continuously monitor communication quality and prepare to switch to independent operation mode. This preliminary preparation ensures that when fire panel failure occurs, the system can immediately transition to degraded mode without adding significant complexity to the basic architecture.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If degraded mode is implemented for independent remote unit communication, then system reliability is improved during communication failures, but device complexity increases

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

Solution Approach 1:

The communication interface in each remote unit is designed with multi-functionality, capable of operating in both master-slave mode (when fire panel is functional) and peer-to-peer mode (when fire panel fails). This universal design allows the same hardware to perform multiple communication functions, achieving improved reliability during failures without proportionally increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 enables the fire system to trigger alarms across the entire loop even when the fire panel cannot function as the master, ensuring continuous emergency notification and reducing reliance on the master-slave communication system, thereby enhancing safety and reliability.

Implementation Method 1

each of the plurality of remote units comprises a current sensor for detecting current in the degraded mode

Methodology Applied
Scientific EffectElectrical current detection: Conduction (electrical)

Data Source

PatentEP4071733B1Fire system with degraded mode of operation
Publication Date: 2024.12.25 CARRIER CORP
  • EP4071733B1 patent drawingFigure 1
  • EP4071733B1 patent drawingFigure 2
  • EP4071733B1 patent drawingFigure 3

AI summary

A fire system 10 for a building is described. The fire system 10 comprises a fire panel 12 for monitoring the building and activating an alarm, the fire panel 10 comprising a loop controller 24; and a plurality of remote units 14, 16, 18 electrically connected to the fire panel 12 in a circuit 20 having a loop configuration, at least one of the plurality of remote units 14, 16, 18 comprising an indicating device 14, 18 for determining conditions that are indicative of a possible emergency and modulating a current in the circuit when those conditions indicate a possible emergency. In normal use the plurality of remote units 14, 16, 18 are in communication with the fire panel 12 in a master-slave relationship. The fire system 10 is configured to enter a degraded mode of operation when failure of the master-slave communications occurs, with the fire panel 12 being configured to create a high output impedance in the circuit 20 and enable a degraded communications mode for the remote units 14, 16, 18 in the degraded mode. Each of the plurality of remote units 14, 16, 18 comprises a current sensor 26 for detecting current in the degraded mode.