Auxiliary Data Transmission Over Alarm Tandem Lines
Solution Overview
Problem
Current smoke and fire alarm tandem line networks are limited in communication to basic alarm triggering frequencies, necessitating a system that can transmit auxiliary data beyond mere alarm presence without triggering false alarms due to noise signals.
Innovation Solution
The implementation of a system with a detector controller and an auxiliary controller that filters signals based on amplitude and frequency thresholds, allowing for the transmission of auxiliary data as short bursts during noise signal peaks or in packets with disruption points, while maintaining the frequency threshold for alarm conditions to prevent false alarms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If alarm signals are transmitted at frequencies lower than the 60 Hz noise threshold, then false alarms are prevented, but communication is limited to basic alarm triggering only
Solution Approach 1:
The patent transmits auxiliary data as periodic pulse trains with specific frequencies and duty cycles. By using periodic bursts of data embedded within the alarm signal framework, the system communicates additional information (device type, location, status) while maintaining the low-frequency carrier wave that prevents false alarms. The periodic nature allows receivers to distinguish between alarm signals and auxiliary data through frequency and timing analysis.
Solution Approach 2:
The patent assigns different frequency characteristics to different types of alarm signals and auxiliary data within the same communication channel. By modulating auxiliary data with specific frequency signatures and duty cycles distinct from standard alarm signals, the system enables selective filtering and interpretation at the receiver端, allowing basic alarm functions to remain simple while enabling sophisticated data communication for advanced applications.
2Reliability
If the frequency threshold is maintained for alarm conditions, then alarm reliability is preserved, but auxiliary data transmission beyond alarm presence is limited
Solution Approach 1:
The patent segments the alarm signal into distinct components: a low-frequency carrier wave for reliable alarm transmission and high-frequency modulated pulses for auxiliary data. By dividing the communication into these functional segments, the system preserves the simplicity and reliability of basic alarm signaling while embedding additional information layers that convey device identity, location, and status without interfering with the primary alarm function.
Solution Approach 2:
The patent adds temporal and spectral dimensions to the alarm communication. Instead of merely varying frequency to encode data, the system uses pulse width modulation, duty cycle variations, and timing patterns as additional encoding dimensions. This multi-dimensional approach allows rich auxiliary data transmission while maintaining the fundamental low-frequency alarm signal structure that ensures reliable operation and false alarm prevention.
3Object-affected harmful factors
If noise filtering is applied to eliminate signals below the frequency threshold, then false alarms are prevented, but auxiliary data signals are also blocked
Solution Approach 1:
The patent converts the presence of 60 Hz noise signals from a harmful interference into a beneficial synchronization reference. By timing auxiliary data transmissions to occur during specific phases of the noise cycle and using the noise frequency as a clock reference, the system ensures that data bursts are transmitted during periods when the noise does not interfere with detection. The noise, rather than being filtered out, becomes part of the transmission timing framework that enables reliable auxiliary data communication.
Data Source
AI summary
A device capable of and method for communicating auxiliary data over an alarm network tandem line, whereby noise signals are filtered. The noise signals have an amplitude less than a first threshold. Further, a tandem signal is transmitted or received via a tandem port, wherein the signal transmitted or received is substantially synchronous with a noise signal peak or the transmission does not contain a period greater than the first duration. The period is measured as between two of: one or more disruption point, packet beginning, and packet finish, adjacently disposed. The disruption point is a point where the tandem signal is below a first amplitude threshold. Further, the combined amplitude of the tandem signal and the noise signal is greater than the first threshold.