Fire-fighting communication system and method based on two-wire system capacitive load switching logic judgment

Abstract

The invention relates to the technical field of fire-fighting call systems, in particular to a fire-fighting call system and method based on two-wire capacitive load switching logic judgment. The system comprises a fire-fighting telephone switchboard and a plurality of fire-fighting telephone extensions, the fire-fighting telephone switchboard and the fire-fighting telephone extensions are connected through a two-wire system bus, the fire-fighting telephone switchboard regulates and controls two amplitudes of voltage A and voltage B output by power supply through the two-wire system bus, and a fixed voltage difference delta U exists between the voltage A and the voltage B; the fire-fighting telephone extension sets sample the voltage of the two-wire system bus in real time and detect the fixed voltage difference delta U so as to be used for controlling the state of energy storage electrolysis in a matched mode. Audio signals input by the fire-fighting telephone switchboard / the fire-fighting telephone extensions are collected by the analog MIC, the signals within a certain frequency range are modulated and demodulated, and the output receiver makes sound. According to the method, the call quality and the loading capacity of the fire protection telephone system are improved, the cost of additionally increasing repeaters due to excessive loading is reduced, the debugging complexity of large park projects is reduced, and the application experience of customers is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fire telephone systems, and in particular to a fire communication system and method based on two-wire capacitive load switching logic judgment. Background Art

[0002] The fire telephone system is a special device for fire communication. When a fire alarm occurs, it can provide a convenient and fast communication means, and is an indispensable communication device in the fire control and alarm system. The fire telephone system has a dedicated communication line. On-site personnel can communicate with the fire telephone main unit in the fire control room through the fixed fire telephone extension set on-site, or use the portable fire telephone extension set in combination with the jack-type manual alarm or the fire telephone jack to communicate with the fire telephone main unit in the control room.

[0003] Currently, the mainstream in the fire telephone system industry is two-wire system. The two buses not only realize the power supply / communication between the fire telephone main unit and the fire telephone extension set, but also realize the communication and exchange between the fire telephone main unit and the fire telephone extension set. For example, the method for realizing the communication between the main and extension sets of the bus fire telephone with automatic addressing disclosed in Patent Publication No. 108769281A. Under normal monitoring conditions, the main and extension sets communicate according to the communication protocols of different manufacturers. To prevent the MCU main chip of the fire telephone extension set from losing power and resetting during the communication process, about 100 uF of energy storage electrolytic capacitors are added to the communication branch of the fire telephone extension set. When a call demand is detected and the handshake communication between the main and extension sets is successful, the MCU chips of the main and extension sets synchronously control to establish a call branch to realize the call between the main and extension sets; since there is no communication during the call process, the main unit judges the call establishment situation by detecting the change of the bus current to realize the switching between call / communication.

[0004] However, there are many problems in the current two-wire fire telephone system. The fire telephone extension set adds a large-capacity energy storage electrolytic capacitor to the communication branch. This electrolytic capacitor extracts the call AC signal during the call. The more fire telephone extension sets are hung on the loop, the more call AC signals are extracted by this energy storage electrolytic capacitor, resulting in less call energy obtained by the call branch and poorer call sound effect. The conversion efficiency of the on-site bus call energy into call audio output is very low. If a repeater is added to the line, additional cost expenditures and system debugging expenditures are required. In the industry, there are generally problems such as small call sound signals for multiple calls, and many load nodes on the system loop affecting the call quality. Most of them improve the call effect by adding repeaters, resulting in additional cost expenditures and system debugging expenditures. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: to overcome the deficiencies of the prior art, provide a fire communication system and method based on two-wire capacitive load switching logic judgment, improve the call quality and load-carrying capacity of the fire telephone system, reduce the cost of additional repeaters required due to excessive loading, reduce the debugging complexity of large campus projects, and improve the application experience of customers.

[0006] The technical solution adopted by the present invention is as follows: A fire communication system based on two-wire capacitive load switching logic judgment, comprising a fire telephone main unit and a plurality of fire telephone extension units, the fire telephone main unit and the fire telephone extension units are connected through a two-wire bus, wherein: The fire telephone main unit regulates two amplitudes of the supply output voltage A and voltage B through the two-wire bus, voltage A is used for communication / supply, voltage B is used for call power supply, and there is a fixed voltage difference ΔU between voltage A and voltage B; the fire telephone main unit is used for real-time sampling and detecting the current change under voltage B, and switching voltage A and voltage B according to the change of the two-wire bus communication under voltage A or the current of the two-wire bus under voltage B; The fire telephone extension unit detects the fixed voltage difference ΔU by real-time sampling of the two-wire bus voltage to match and control the state of the energy storage electrolytic MUC-I / O port; in the communication state, voltage A is supplied between the fire telephone main unit and the fire telephone extension unit. When the main unit calls the extension unit / the extension unit calls the main unit, events are sent down or reported through the two-wire bus. If not connected, the current of the two-wire bus does not change and current detection is no longer performed; if connected, the fire telephone main unit issues a broadcast command, the fire telephone extension unit cuts off the storage power supply, and at the same time the fire telephone main unit switches to output voltage B, and the fire telephone main unit real-time samples the current of the two-wire bus under voltage B; The input audio signal of the fire telephone main unit / fire telephone extension unit is collected by an analog MIC, modulated and demodulated for signals within a certain frequency range, and output to a receiver for sound output.

[0007] This technical solution is based on the capacitive load switching logic of a two-wire system. By regulating the voltage amplitude output by the fire telephone main unit and performing switching during communication and calls, it effectively solves the influence of energy storage electrolysis on call signals. The energy storage electrolysis is connected to the system during communication and disconnected from the system during calls, thus avoiding the absorption of call signals by the energy storage electrolysis and improving call quality. Specifically, communication and power supply between the fire telephone main unit and the extension are achieved through a two-wire bus. The main unit can regulate and output two voltage amplitudes. Voltage A is used for daily communication and power supply, while voltage B is specifically used for call power supply, allowing the system to use different voltages in different working modes to optimize performance and efficiency. The fixed voltage difference ΔU between voltage A and voltage B provides a stable voltage switching reference for the system. During the communication process, the main unit judges the call status by detecting the current change under voltage B through real-time sampling. Once a call demand is detected, the main unit switches to voltage B for power supply and monitors the current change to confirm the establishment of the call, achieving efficient calls. The fire telephone extension controls the connection and disconnection of the energy storage electrolysis by detecting the fixed voltage difference ΔU through real-time sampling of the two-wire bus voltage. In the communication state, the energy storage electrolysis provides power for the extension. In the call state, the energy storage electrolysis is disconnected to avoid its absorption of call AC signals and affecting call quality, solving the problem of interference of energy storage electrolysis on call signals in traditional systems. In addition, the input audio signal is collected through an analog MIC, then the signal within a specific frequency range is modulated and demodulated, and finally output through the output receiver to ensure high-quality transmission and reception of the audio signal.

[0008] In addition, the fire communication system proposed above based on the two-wire capacitive load switching logic according to the present invention further has the following additional technical features: According to an embodiment of the present invention, the analog MIC modulates and demodulates signals within the range of 300 Hz - 3400 Hz through an IC chip.

[0009] In this technical solution, the analog MIC, as the front-end device for audio signal collection, can convert the sound signal in the environment into an electrical signal. The IC chip is responsible for modulating and demodulating this electrical signal, optimizing the signal within the range of 300 Hz - 3400 Hz. This frequency range covers the main audible frequency bands of the human ear, including the main frequencies of voice communication. The modulation and demodulation process converts the analog signal into a digital signal. The output receiver converts the processed digital signal back into an analog signal and outputs it in the form of sound.

[0010] According to an embodiment of the present invention, in the control port circuit of the fire telephone main unit, a voltage regulation unit is provided for outputting two amplitudes of voltage A and voltage B and ensuring a fixed voltage difference ΔU therebetween; the power supply switching control port MCU-PWM of the fire telephone main unit controls the relay to switch the output of voltage A and voltage B through the MOS transistor VM1; the call current sampling port MCU-AD of the fire telephone main unit detects the current change under voltage B in real time through R2 to judge the call state.

[0011] According to an embodiment of the present invention, in the control port circuit of the fire telephone extension, a bus voltage detection unit is provided. When the detected fixed voltage difference ΔU changes, the energy storage electrolysis switching control port MCU-I / O outputs a corresponding control signal to control the removal of the energy storage electrolysis through a triode; the call branch control port MCU-EN of the fire telephone extension turns on the call branch through a triode.

[0012] According to an embodiment of the present invention, when the fire telephone extension is powered on for the first time, the power supply pull-up resistor R4 is used in the control port circuit to ensure that the fire telephone extension enters the normal working state when powered on for the first time.

[0013] The present invention also provides a fire communication method based on two-wire capacitive load switching logic judgment.

[0014] A fire communication method based on two-wire capacitive load switching logic judgment includes the following steps: S1. Establish a fire communication system: including a fire telephone main unit and a plurality of fire telephone extensions, the fire telephone main unit communicates and makes calls with the fire telephone extensions through a two-wire bus, and the two-wire bus regulates two amplitudes of voltage A and voltage B; S2. Set the capacitive load switching logic: The fire telephone main unit outputs voltage A and voltage B. Voltage A is used for communication / power supply, and voltage B is used for calls. There is a fixed voltage difference ΔU between voltage A and voltage B, including the following sub-steps: S21. Voltage switching and detection: In the communication state, the fire telephone main unit and the fire telephone extension use voltage A to supply power to the fire telephone. When a call demand is detected, the fire telephone main unit switches to voltage B for power supply and detects the current change under voltage B in real time; S22. Voltage detection and control: The fire telephone extension adds a bus voltage detection unit for detecting the voltage difference ΔU on the two-wire bus; when the detected fixed voltage difference ΔU changes, the fire telephone extension removes or reconnects the energy storage electrolysis from the system according to the control logic; S3. Intelligent control of energy storage electrolysis: When the fire telephone extension is powered on for the first time, the energy storage electrolysis is connected to the circuit to ensure that the fire telephone extension enters the normal working state; during communication, the energy storage electrolysis is connected to the system to provide communication power supply for the fire telephone extension; when a call is established, the fire telephone main unit switches to power supply with voltage B. After the fire telephone extension detects a fixed pressure difference ΔU, the energy storage electrolysis is cut off from the system to avoid its absorption of the call signal; when the fire telephone main unit needs to send a communication event, it first switches to power supply with voltage A. After the fire telephone extension detects a fixed pressure difference ΔU, the energy storage electrolysis is connected back to the system to ensure that the fire telephone extension can normally receive the communication event. S4. Timing control of system cooperation: The cooperation timing between the fire telephone main unit and the fire telephone extension completes voltage switching, energy storage electrolysis on / off, and event sending within milliseconds to achieve the response of the fire communication system.

[0015] This technical solution ensures the effective avoidance of the absorption of call signals by the energy storage electrolysis during a call and improves the clarity and stability of the call by establishing a fire communication system, setting the switching logic of capacitive loads, realizing the intelligent control of energy storage electrolysis, and the timing control of system cooperation. Specifically, by establishing a call system including a fire telephone main unit and multiple fire telephone extensions, communicating and making calls using a two-wire bus, and being able to regulate two amplitudes of voltage A and voltage B on the bus; in the communication state, power supply with voltage A is used; when a call demand is detected, it quickly switches to power supply with voltage B and real-time detects the current change under voltage B to ensure the call quality; to cooperate with the voltage switching of the main unit, the fire telephone extension adds a bus voltage detection unit. When detecting a change in the fixed pressure difference ΔU, the extension flexibly controls the connection and disconnection of the energy storage electrolysis according to the preset control logic; when the fire telephone extension is powered on for the first time, the energy storage electrolysis is connected to the circuit to ensure that the extension can start normally and enter the working state; during communication, the energy storage electrolysis continuously provides power support for the extension; when a call is established, the main unit switches to power supply with voltage B. After the extension detects a fixed pressure difference ΔU, it quickly cuts off the energy storage electrolysis from the system to avoid its interference with the call signal; when the main unit needs to send a communication event, it first switches to power supply with voltage A. After the extension detects a fixed pressure difference ΔU again, the energy storage electrolysis is connected back to the system to ensure that the extension can normally receive the communication event; through the timing control of system cooperation, the fire telephone main unit and the extension can complete voltage switching, energy storage electrolysis on / off, and event sending within milliseconds to ensure the quick response and stable operation of the fire communication system.

[0016] According to an embodiment of the present invention, in S4, for a single call, when the fire telephone console calls the extension, the fire telephone console / extension is powered and communicates at voltage A. After the fire telephone extension is connected, the communication handshake between the fire telephone console / extension is successful. The fire telephone console switches to output voltage B, and the fire telephone extension cuts off the energy storage electrolytic branch; the call loop of the fire telephone console / extension is connected to establish a call; the fire telephone console samples the bus current at voltage B in real time, and the fire telephone extension samples the bus voltage in real time; when the fire telephone extension hangs up the call / closes the call loop, the fire telephone console samples and detects the change in the bus current at voltage B; the fire telephone console closes the call loop, the fire telephone console switches to voltage A, the fire telephone extension detects the bus pressure difference ΔU, and reconnects the energy storage electrolytic to the branch; when the fire telephone extension receives the inspection frame and reports the hang-up event, the fire telephone console completes the event confirmation; when the call ends, the fire telephone console stops detecting the change in the bus current, and the fire telephone extension stops detecting the change in the bus voltage.

[0017] According to an embodiment of the present invention, in S4, for a single call, when the fire telephone extension calls the console, the fire telephone main unit / extension is powered and communicates at voltage A. After the fire telephone console is connected, the communication handshake between the fire telephone console / extension is successful; the fire telephone console switches to output voltage B, and the fire telephone extension cuts off the energy storage electrolytic branch; the call loop of the fire telephone console / extension is connected to establish a call; the fire telephone console samples the bus current at voltage B in real time, and the fire telephone extension samples the bus voltage in real time; when the fire telephone console hangs up the call / closes the call loop; the fire telephone console switches to voltage A, the fire telephone extension detects the bus pressure difference ΔU, reconnects the energy storage electrolytic to the branch, and closes the call loop; the fire telephone console communicates and issues a hang-up event, and the fire telephone extension completes the event confirmation; when the call ends, the fire telephone console stops detecting the change in the bus current, and the fire telephone extension stops detecting the change in the bus voltage.

[0018] According to an embodiment of the present invention, in S4, for multiple calls, if the fire telephone console calls the extension, the fire telephone console closes the call loop and switches to voltage A. The fire telephone extension detects the bus pressure difference ΔU. When the extension in the call closes the call loop, all the extensions on the line reconnect the energy storage electrolytic to the branch; the fire telephone console communicates and issues an event, and all the extensions on the line cut off the energy storage electrolytic branch, and all the extensions that have established a call reconnect to the call loop; the fire telephone console switches to voltage B and connects the call loop. When the called fire telephone extension connects to the call branch, the fire telephone console samples and detects the change in the voltage B bus current. The fire telephone console closes the call loop and switches to voltage A. The fire telephone extension detects the bus pressure difference U. During the call, the extension closes the call loop. All extensions on the line connect the energy storage electrolytic back to the branch. The fire telephone extension receives the inspection frame and reports the connection event. The fire telephone console confirms the event and completes it. The fire telephone console / extension confirms the establishment of the call. All extensions on the line cut off the energy storage electrolytic branch, and all extensions that have established the call connect back to the call loop. The fire telephone console switches to voltage B and connects the call loop. When the fire telephone console hangs up the call, the fire telephone console closes the call loop, switches to voltage A. The fire telephone extension detects the bus pressure difference ΔU and connects the energy storage electrolytic back to the branch. The fire telephone console communicates and issues the hang-up event. The fire telephone extension confirms the event and closes the call loop. The fire telephone console / extension cancels the establishment of the call. The console confirms whether there are other extensions establishing the call. All extensions on the line cut off the energy storage electrolytic branch, and all extensions that have established the call connect back to the call loop. The fire telephone console switches to voltage B and connects the call loop.

[0019] According to an embodiment of the present invention, in S4, for multiple calls, when the fire telephone extension calls the console, the fire telephone extension connects to the call branch. The fire telephone console samples and detects the change in the B-source bus current. The fire telephone console closes the call loop and switches to voltage A. The fire telephone extension detects the bus pressure difference ΔU. During the call, the extension closes the call loop. All extensions on the line connect the energy storage electrolytic back to the branch. The fire telephone extension receives the inspection frame and reports the call event. The fire telephone console confirms the event and issues the event. All extensions on the line cut off the energy storage electrolytic branch, and all extensions that have established the call connect back to the call loop. The fire telephone console switches to voltage B and connects the call loop. When the fire telephone main unit presses a key to connect the call, the fire telephone console closes the call loop and switches to voltage A. The fire telephone extension detects the bus pressure difference ΔU. During the call, the extension closes the call loop. All extensions on the line connect the energy storage electrolytic back to the branch. The fire telephone main unit communicates and issues the connection event. The fire telephone extension confirms the event and completes it. The fire telephone console / extension confirms the establishment of the call. All extensions on the line cut off the energy storage electrolytic branch, and all extensions that have established the call connect back to the call loop. The fire telephone console switches to voltage B and connects the call loop. When the fire telephone extension hangs up the call, the fire telephone extension closes the call loop, and the fire telephone main unit detects the change of voltage B bus current; when the fire telephone main unit closes the call loop, the fire telephone main unit switches to voltage A; when the fire telephone extension detects the bus pressure difference AU, and during the call, the extension closes the call loop, and all extensions on the line will connect the energy storage electrolytic back to the branch; when the fire telephone extension receives the patrol frame and reports the hang-up event, the fire telephone main unit completes the event confirmation; when the fire telephone main / extension cancels the call establishment, the main unit confirms whether there are other extensions establishing calls; all extensions on the line cut off the energy storage electrolytic branch, and all extensions establishing calls connect back to the call loop; the fire telephone main unit switches to voltage B to connect the call loop.

[0020] Compared with the prior art, the present invention has the following beneficial effects: (1) When in call, the problem that the energy storage electrolytic is cut off from the system and connected back to the branch during communication is effectively solved, and the problem of low call sound in the fire telephone system loop is solved from the root cause; (2) It can achieve 128 fire telephone extensions mounted on the loop and communicate with 5 fire telephone extensions at the same time. In the industry, it is basically limited to mounting 64 fire telephone extensions / communicating with 2 fire telephone extensions at the same time, greatly improving the number of mounted / simultaneous calls, and significantly enhancing the customer application experience effect; (3) It reduces the cost of additional repeaters required for large campus projects due to excessive loading, and reduces the commissioning complexity of large campus projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the flow schematic diagram of the method of the present invention.

[0022] Figure 2 is the circuit diagram of the control port of the fire telephone main unit.

[0023] Figure 3 is the circuit diagram of the control port of the fire telephone extension.

[0024] Figure 4 is the principle waveform diagram of the energy storage electrolytic before single-load single-call.

[0025] Figure 5 is the principle waveform diagram of the energy storage electrolytic before double-load double-call.

[0026] Figure 6 is the principle waveform diagram of the energy storage electrolytic removal for single-load single-call.

[0027] Figure 7 is the principle waveform diagram of the energy storage electrolytic removal for multi-load multi-call.

[0028] Figure 8 is the principle waveform diagram of the energy storage electrolytic with single-load single-call.

[0029] Figure 9 It is the waveform diagram of the energy storage electrolysis principle for a single call with different loads. Specific implementation mode

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] Embodiment 1 As Figures 1 to 9 shown, this embodiment provides a fire communication system based on two-wire capacitive load switching logic judgment, including a fire telephone main unit and several fire telephone extension units. The fire telephone main unit and the fire telephone extension units are connected through a two-wire bus. Among them: The fire telephone main unit regulates the voltages A and B with two amplitudes of the power supply output through the two-wire bus. Voltage A is used for communication / power supply, and voltage B is used for call power supply. There is a fixed voltage difference ΔU between voltage A and voltage B. The fire telephone main unit is used to sample and detect the current change under voltage B in real time, and switch between voltage A and voltage B according to the change of two-wire bus communication under voltage A or the change of two-wire bus current under voltage B; The fire telephone extension unit detects the fixed voltage difference ΔU by sampling the two-wire bus voltage in real time to match and control the state of the energy storage electrolysis MUC-I / O port. In the communication state, voltage A is supplied between the fire telephone main unit and the fire telephone extension unit. When the main unit calls the extension unit / the extension unit calls the main unit, the event is sent down or reported through the two-wire bus. If not connected, the two-wire bus current does not change and the current detection is no longer performed. If connected, the fire telephone main unit issues a broadcast command, the fire telephone extension unit cuts off the storage power supply, and at the same time the fire telephone main unit switches the output of voltage B, and the fire telephone main unit samples the two-wire bus current under voltage B in real time; The input audio signal of the fire telephone main unit / fire telephone extension unit is collected by an analog MIC, modulated and demodulated for signals within a certain frequency range, and output to the receiver for sound output.

[0032] This technical solution is based on the capacitive load switching logic of the two-wire system. By regulating the voltage amplitude output by the fire telephone main unit and performing switching during communication and call processes, it effectively solves the influence of energy storage electrolysis on call signals. The energy storage electrolysis is connected to the system during communication and cut off from the system during calls, thus avoiding the absorption of call signals by the energy storage electrolysis and improving call quality. Specifically, communication and power supply between the fire telephone main unit and the extension are achieved through a two-wire bus. The main unit can regulate and output two voltage amplitudes. Among them, voltage A is used for daily communication and power supply, while voltage B is specifically used for call power supply, allowing the system to use different voltages in different working modes to optimize performance and efficiency. The fixed voltage difference ΔU between voltage A and voltage B provides a stable voltage switching reference for the system. During the communication process, the main unit judges the call status by detecting the current change under voltage B through real-time sampling. Once a call demand is detected, the main unit will switch to voltage B for power supply and monitor the current change to confirm the establishment of the call, achieving efficient calls. The fire telephone extension controls the connection and disconnection of the energy storage electrolysis by real-time sampling the two-wire bus voltage and detecting the fixed voltage difference ΔU. In the communication state, the energy storage electrolysis provides power for the extension. In the call state, the energy storage electrolysis is cut off to avoid its absorption of call AC signals and affecting call quality, solving the problem of interference of energy storage electrolysis on call signals in traditional systems. In addition, the input audio signal is collected through an analog MIC, then the signal within a specific frequency range is modulated and demodulated, and finally output through the output receiver to ensure high-quality transmission and reception of the audio signal.

[0033] In addition, the fire communication system proposed above based on the two-wire capacitive load switching logic judgment according to the present invention further has the following additional technical features: According to an embodiment of the present invention, the analog MIC modulates and demodulates signals in the range of 300 Hz - 3400 Hz through an IC chip.

[0034] In this technical solution, the analog MIC, as the front-end device for audio signal collection, can convert the sound signal in the environment into an electrical signal. The IC chip is responsible for modulating and demodulating this electrical signal, optimizing the signals in the range of 300 Hz - 3400 Hz. This frequency range covers the main audible frequency bands of the human ear, including the main frequencies of voice communication. The modulation and demodulation process converts the analog signal into a digital signal. The output receiver converts the processed digital signal back into an analog signal and outputs it in the form of sound.

[0035] As Figure 2As shown in the figure, in the control port circuit of the fire telephone main unit, a voltage regulation unit is provided, which is used to output two amplitudes of voltage A and voltage B, and ensure that there is a fixed voltage difference ΔU between the two; the power supply switching control port MCU-PWM of the fire telephone main unit controls the relay to switch the output of voltage A and voltage B through the MOS tube VM1; the call current sampling port MCU-AD of the fire telephone main unit detects the current change under voltage B in real time through R2 to judge the call state.

[0036] As Figure 3 shown in the figure, in the control port circuit of the fire telephone extension, a bus voltage detection unit is provided. When the detected fixed voltage difference ΔU changes, the energy storage electrolysis switching control port MCU-I / O outputs a corresponding control signal, and controls the removal of the energy storage electrolysis through a triode; the call branch control port MCU-EN of the fire telephone extension turns on the call branch through a triode.

[0037] According to an embodiment of the present invention, when the fire telephone extension is powered on for the first time, in the control port circuit, through the power supply pull-up resistor R4, it is ensured that the fire telephone extension enters the normal working state when powered on for the first time.

[0038] Embodiment 2 On the basis of Embodiment 1, as Figure 1 shown in the figure, this embodiment provides a fire call method based on two-wire capacitive load switching logic judgment, including the following steps: S1. Establish a fire call system: including a fire telephone main unit and several fire telephone extensions. The fire telephone main unit communicates and makes calls with the fire telephone extensions through a two-wire bus, and the two-wire bus regulates two amplitudes of voltage A and voltage B; S2. Set the capacitive load switching logic: The fire telephone main unit outputs voltage A and voltage B. Voltage A is used for communication / power supply, and voltage B is used for calls. There is a fixed voltage difference ΔU between voltages A and B, including the following sub-steps: S21. Voltage switching and detection: In the communication state, the fire telephone main unit supplies power to the fire telephone extension using voltage A. When a call demand is detected, the fire telephone main unit switches to voltage B for power supply and detects the current change under voltage B in real time; S22. Voltage detection and control: The fire telephone extension adds a bus voltage detection unit to detect the voltage difference ΔU on the two-wire bus; when the detected fixed voltage difference ΔU changes, the fire telephone extension removes or reconnects the energy storage electrolysis from the system according to the control logic; S3. Intelligent control of energy storage electrolysis: When the fire telephone extension is powered on for the first time, the energy storage electrolysis is connected to the circuit to ensure that the fire telephone extension enters the normal working state; during communication, the energy storage electrolysis is connected to the system to provide communication power supply for the fire telephone extension; when a call is established, the fire telephone main unit switches to supply power with voltage B. After the fire telephone extension detects a fixed pressure difference ΔU, the energy storage electrolysis is cut off from the system to avoid its absorption of the call signal; when the fire telephone main unit needs to send a communication event, it first switches to supply power with voltage A. After the fire telephone extension detects a fixed pressure difference ΔU, the energy storage electrolysis is connected back to the system to ensure that the fire telephone extension can normally receive the communication event; S4. Timing control of system cooperation: The cooperation timing between the fire telephone main unit and the fire telephone extension completes voltage switching, energy storage electrolysis connection and disconnection, and event sending within milliseconds to achieve the response of the fire communication system.

[0039] This technical solution ensures that the absorption of the call signal by the energy storage electrolysis can be effectively avoided during the call, and improves the clarity and stability of the call by establishing a fire communication system, setting the switching logic of capacitive loads, realizing the intelligent control of energy storage electrolysis, and the timing control of system cooperation. Specifically, by establishing a call system including a fire telephone main unit and multiple fire telephone extensions, using a two-wire bus for communication and calls, and being able to regulate two amplitudes of voltage A and voltage B on the bus; in the communication state, voltage A is used for power supply; when a call demand is detected, it quickly switches to supply power with voltage B and real-time detects the current change under voltage B to ensure the call quality; to cooperate with the voltage switching of the main unit, the fire telephone extension adds a bus voltage detection unit. When detecting a change in the fixed pressure difference ΔU, the extension flexibly controls the connection and disconnection of the energy storage electrolysis according to the preset control logic; when the fire telephone extension is powered on for the first time, the energy storage electrolysis is connected to the circuit to ensure that the extension can start normally and enter the working state; during communication, the energy storage electrolysis continuously provides power support for the extension; when a call is established, the main unit switches to supply power with voltage B. After the extension detects a fixed pressure difference ΔU, it quickly cuts off the energy storage electrolysis from the system to avoid its interference with the call signal; when the main unit needs to send a communication event, it will first switch to supply power with voltage A. After the extension detects a fixed pressure difference ΔU again, the energy storage electrolysis is connected back to the system to ensure that the extension can normally receive the communication event; through the timing control of system cooperation, the fire telephone main unit and the extension can complete voltage switching, energy storage electrolysis connection and disconnection, and event sending within milliseconds to ensure the fast response and stable operation of the fire communication system.

[0040] According to an embodiment of the present invention, in S4, for a single call, when the fire telephone console calls the extension, the fire telephone console / extension is powered for communication at voltage A. After the fire telephone extension is connected, the communication handshake between the fire telephone console / extension is successful. The fire telephone console switches to output voltage B, and the fire telephone extension cuts off the energy storage electrolytic branch; the call loop of the fire telephone console / extension is connected to establish a call; the fire telephone console samples the bus current at voltage B in real time, and the fire telephone extension samples the bus voltage in real time; when the fire telephone extension hangs up the call / closes the call loop, the fire telephone console samples and detects the change in the bus current at voltage B; the fire telephone console closes the call loop, the fire telephone console switches to voltage A, the fire telephone extension detects the bus pressure difference ΔU, and reconnects the energy storage electrolytic to the branch; when the fire telephone extension receives the inspection frame and reports the hang-up event, the fire telephone console completes the event confirmation; when the call ends, the fire telephone console stops detecting the change in the bus current, and the fire telephone extension stops detecting the change in the bus voltage.

[0041] According to an embodiment of the present invention, in S4, for a single call, when the fire telephone extension calls the console, the fire telephone main unit / extension is powered for communication at voltage A. After the fire telephone console is connected, the communication handshake between the fire telephone console / extension is successful; the fire telephone console switches to output voltage B, and the fire telephone extension cuts off the energy storage electrolytic branch; the call loop of the fire telephone console / extension is connected to establish a call; the fire telephone console samples the bus current at voltage B in real time, and the fire telephone extension samples the bus voltage in real time; when the fire telephone console hangs up the call / closes the call loop; the fire telephone console switches to voltage A, the fire telephone extension detects the bus pressure difference ΔU, reconnects the energy storage electrolytic to the branch, and closes the call loop; the fire telephone console communicates and issues a hang-up event, and the fire telephone extension completes the event confirmation; when the call ends, the fire telephone console stops detecting the change in the bus current, and the fire telephone extension stops detecting the change in the bus voltage.

[0042] According to an embodiment of the present invention, in S4, for multiple calls, if the fire telephone console calls the extension, the fire telephone console closes the call loop and switches to voltage A. The fire telephone extension detects the bus pressure difference ΔU. When the extension in the call closes the call loop, all the extensions on the line reconnect the energy storage electrolytic to the branch; the fire telephone console communicates and issues an event, and all the extensions on the line cut off the energy storage electrolytic branch, and all the extensions that have established a call reconnect to the call loop; the fire telephone console switches to voltage B and connects the call loop. When the called fire telephone extension connects to the call branch, the fire telephone console samples and detects changes in the voltage of Bus B and the current. The fire telephone console closes the call loop and switches to Voltage A. The fire telephone extension detects the bus pressure difference U. During the call, the extension closes the call loop, and all extensions on the line reconnect the energy storage electrolytic capacitor to the branch. The fire telephone extension receives the inspection frame and reports the connection event. The fire telephone console confirms the event and completes it. The fire telephone console / extension confirms the establishment of the call. All extensions on the line cut off the energy storage electrolytic capacitor branch, and all extensions that have established the call reconnect to the call loop. The fire telephone console switches to Voltage B and connects the call loop. When the fire telephone console hangs up the call, the fire telephone console closes the call loop, switches to Voltage A, and the fire telephone extension detects the bus pressure difference ΔU and reconnects the energy storage electrolytic capacitor to the branch. The fire telephone console sends a communication to issue a hang-up event, and the fire telephone extension confirms the event and closes the call loop. The fire telephone console / extension cancels the establishment of the call, and the console confirms whether there are other extensions establishing a call. All extensions on the line cut off the energy storage electrolytic capacitor branch, and all extensions that have established the call reconnect to the call loop. The fire telephone console switches to Voltage B and connects the call loop.

[0043] According to an embodiment of the present invention, in S4, for multiple calls, when the fire telephone extension calls the console, the fire telephone extension connects to the call branch, and the fire telephone console samples and detects changes in the current of Bus B of the B source. The fire telephone console closes the call loop and switches to Voltage A. The fire telephone extension detects the bus pressure difference ΔU. During the call, the extension closes the call loop, and all extensions on the line reconnect the energy storage electrolytic capacitor to the branch. The fire telephone extension receives the inspection frame and reports the call event. The fire telephone console confirms the event and issues the event. All extensions on the line cut off the energy storage electrolytic capacitor branch, and all extensions that have established the call reconnect to the call loop. The fire telephone console switches to Voltage B and connects the call loop. When the fire telephone main unit presses a key to connect the call, the fire telephone console closes the call loop and switches to Voltage A. The fire telephone extension detects the bus pressure difference ΔU. During the call, the extension closes the call loop, and all extensions on the line reconnect the energy storage electrolytic capacitor to the branch. The fire telephone main unit sends a communication to issue a connection event, and the fire telephone extension confirms the event and completes it. The fire telephone console / extension confirms the establishment of the call. All extensions on the line cut off the energy storage electrolytic capacitor branch, and all extensions that have established the call reconnect to the call loop. The fire telephone console switches to Voltage B and connects the call loop. When the fire telephone extension hangs up the call, the fire telephone extension closes the call loop, and the fire telephone main unit detects the change of voltage B bus current; when the fire telephone main unit closes the call loop, the fire telephone main unit switches to voltage A; when the fire telephone extension detects the bus pressure difference AU and is in a call, the extension closes the call loop, and all extensions on the line connect the energy storage electrolytic capacitor back to the branch; when the fire telephone extension receives the inspection frame and reports the hang-up event, the fire telephone main unit completes the event confirmation; when the fire telephone main / extension cancels the call establishment, the main unit confirms whether there are other extensions establishing calls; all extensions on the line cut off the energy storage electrolytic capacitor branch, and all extensions that have established calls connect back to the call loop; the fire telephone main unit switches to voltage B and connects to the call loop.

[0044] Embodiment 3 Calculation example of current sharing in the call branch.

[0045] For the call, the IC chip is used to modulate and demodulate the signal in the range of 300Hz - 3400Hz. The AC equivalent impedance of its call branch is 620Ω. The general energy storage electrolytic capacitance value in the industry is about 100uF. Ignoring the remaining stray capacitance / line capacitance / other small capacitance ceramic capacitors, taking the 300Hz signal as an example, the AC impedance of the communication branch can be calculated as Z = 1 / 2Πfc (Π is a constant 3.14, f is the frequency 300Hz, C is the capacitance value 100uF) = 1 / (2×3.14×300×100×10⁻⁶) ≈ 5.3Ω. The communication loop and the call loop are in a parallel relationship. At this time, the current sharing ratio of the call loop is 5.3 / (5.3 + 620)×100 ≈ 0.85%.

[0046] Usually, a resistance value is connected in series before the energy storage electrolytic capacitor to improve it, such as Figure 4 shown. There are differences in the applications of each manufacturer. Taking 2KΩ as an example, recalculating, the current sharing ratio of the call loop can be obtained as (5.3 + 2000) / (5.3 + 620 + 2000)×100 ≈ 76.4%. This is for a single load and a single call.

[0047] If it is for two loads and two calls, then the current sharing ratio of the call loop is [(5.3 + 2000) / 2] / [(5.3 + 2000) / 2 + (620 / 2)]×100 ≈ 76.4%. The current shared by the call loop of a single extension is 76.4% / 2 = 38.2%, as Figure 5 shown.

[0048] If the 100uF energy storage electrolytic capacitor is removed during the call, and the remaining stray capacitance / line capacitance / other small capacitance ceramic capacitors are calculated as 10nF, then the AC impedance of the communication branch Z = 1 / 2Πfc ≈ 53KΩ. Similarly, the current sharing ratio of the call loop for a single load and a single call is about 98.9%, as Figure 6 shown.

[0049] If the number of fire telephone extensions increases, taking 20 units as an example and with a single call, the current taken by the energy storage electrolytic call branch is approximately [(5.3 + 2000) / 20] / [(5.3 + 2000) / 20 + 620]×100 ≈ 13.9% (load resistors in parallel); the current taken by the call branch without energy storage electrolysis is approximately [(5.3 + 53K) / 20] / [(5.3 + 53K) / 20 + 620]×100 ≈ 81%, as Figure 7 shown.

[0050] Similarly, the current ratios taken by the call branches during multiple calls with different loads are as shown in the following table: Table 1

[0051] Table 2

[0052] Through actual tests, taking the waveform comparison diagram of a single call with 64 loads as an example, as shown in Figure 8 and Figure 9 shown, the actual test values are basically matched with the calculated values, the call effect has been greatly improved, and there is no problem with 5 simultaneous calls for 128 loads with a wire diameter of 2.0 mm² and a length of 1800 m for the actual product.

Claims

1. A fire communication system based on two-wire capacitive load switching logic judgment, characterized in that, It includes a fire telephone main unit and several fire telephone extension units. The fire telephone main unit and the fire telephone extension units are connected by a two-wire bus. Among them: The fire telephone main unit regulates the voltage amplitudes of voltage A and voltage B of the power supply output through the two-wire bus. Voltage A is used for communication / power supply, and voltage B is used for call power supply. There is a fixed voltage difference ΔU between voltage A and voltage B. The fire telephone main unit is used to sample and detect the current change under voltage B in real time, and switch between voltage A and voltage B according to the change of the two-wire bus communication under voltage A or the current of the two-wire bus under voltage B. The fire telephone extension unit detects the fixed voltage difference ΔU by sampling the two-wire bus voltage in real time to match and control the state of the energy storage electrolytic MUC-I / O port. In the communication state, voltage A is supplied between the fire telephone main unit and the fire telephone extension unit. When the main unit calls the extension unit / the extension unit calls the main unit, the event is sent down or reported through the two-wire bus. If not connected, the current of the two-wire bus does not change and the current detection is no longer carried out. If connected, the fire telephone main unit issues a broadcast command, the fire telephone extension unit cuts off the storage power supply, and at the same time the fire telephone main unit switches the output of voltage B, and the fire telephone main unit samples the current of the two-wire bus under voltage B in real time. The input audio signal of the fire telephone main unit / the fire telephone extension unit is collected by the analog MIC, modulated and demodulated for signals within a certain frequency range, and output to the receiver for sound output.

2. The fire communication system based on the two-wire capacitive load switching logic judgment according to claim 1, wherein, The analog MIC modulates and demodulates signals in the range of 300Hz - 3400Hz through the IC chip.

3. The fire communication system based on the two-wire capacitive load switching logic judgment as described in claim 1, wherein In the control port circuit of the fire telephone main unit, a voltage regulation unit is provided to output the voltage amplitudes of voltage A and voltage B and ensure that there is a fixed voltage difference ΔU between the two. The power supply switching control port MCU-PWM of the fire telephone main unit controls the relay to switch the output of voltage A and voltage B through the MOS tube VM1. The call current sampling port MCU-AD of the fire telephone main unit samples and detects the current change under voltage B in real time through R2 to judge the call state.

4. The fire communication system based on the two-wire capacitive load switching logic judgment according to claim 1, wherein, In the control port circuit of the fire telephone extension unit, a bus voltage detection unit is provided. When the detected fixed voltage difference ΔU changes, the energy storage electrolytic switching control port MCU-I / O outputs a corresponding control signal to control the removal of the energy storage electrolytic through the triode. The call branch control port MCU-EN of the fire telephone extension unit turns on the call branch through the triode.

5. The fire communication system based on the two-wire capacitive load switching logic judgment according to claim 1, wherein For the fire telephone extension unit, when powered on for the first time, the power supply pull-up resistor R4 is used in the control port circuit to ensure that the fire telephone extension unit enters the normal working state when powered on for the first time.

6. A fire communication method based on two-wire capacitive load switching logic judgment, which uses the fire communication system based on two-wire capacitive load switching logic judgment described in any one of claims 1-5, characterized in that, It includes the following steps: S1. Establish a fire call system: It includes a fire telephone main unit and several fire telephone extension units. The fire telephone main unit communicates and makes calls with the fire telephone extension units through a two-wire bus, and the two-wire bus regulates the voltage amplitudes of voltage A and voltage B. S2. Set the capacitive load switching logic: The fire telephone main unit outputs voltage A and voltage B. Voltage A is used for communication / power supply, and voltage B is used for calls. There is a fixed voltage difference ΔU between voltage A and voltage B. It includes the following sub-steps: S21. Voltage switching and detection: In the communication state, the fire telephone main unit and the fire telephone extension are powered by voltage A for the fire telephone. When a call demand is detected, the fire telephone main unit switches to voltage B for power supply and samples and detects the current change under voltage B in real time; S22. Voltage detection and control: The fire telephone extension adds a bus voltage detection unit to detect the voltage difference ΔU on the two-wire bus; when the detected fixed pressure difference ΔU changes, the fire telephone extension removes or reconnects the energy storage electrolytic capacitor from the system according to the control logic; S3. Intelligent control of the energy storage electrolytic capacitor: When the fire telephone extension is powered on for the first time, the energy storage electrolytic capacitor is connected to the circuit to ensure that the fire telephone extension enters the normal working state; During the communication process, the energy storage electrolytic capacitor is connected to the system to provide communication power supply for the fire telephone extension; when a call is established, the fire telephone main unit switches to voltage B for power supply. After the fire telephone extension detects the fixed pressure difference ΔU, it removes the energy storage electrolytic capacitor from the system to avoid its absorption of the call signal; when the fire telephone main unit needs to send a communication event, it first switches to voltage A for power supply. After the fire telephone extension detects the fixed pressure difference ΔU, it reconnects the energy storage electrolytic capacitor to the system to ensure that the fire telephone extension can normally receive the communication event; S4. Timing control of system cooperation: The timing process between the fire telephone main unit and the fire telephone extension completes voltage switching, energy storage electrolytic capacitor on / off, and event sending within milliseconds to achieve the response of the fire communication system.

7. The fire communication method based on two-wire capacitive load switching logic judgment according to claim 6, wherein, In S4, for a single call, when the fire telephone main unit calls the extension, the fire telephone main unit / extension is powered for communication under voltage A. After the fire telephone extension is connected, the communication handshake between the fire telephone main unit / extension is successful. The fire telephone main unit switches the voltage to output voltage B, and the fire telephone extension cuts off the energy storage electrolytic capacitor branch; The call loop of the fire telephone main / extension is connected to establish a call; The fire telephone main unit samples the bus current under voltage B in real time, and the fire telephone extension samples the bus voltage in real time; The fire telephone extension hangs up the call / closes the call loop, and the fire telephone main unit samples and detects the change in the bus current of voltage B; the fire telephone main unit closes the call loop, the fire telephone main unit switches to voltage A, the fire telephone extension detects the bus pressure difference ΔU, and reconnects the energy storage electrolytic capacitor to the branch; when the fire telephone extension receives the inspection frame and reports the hang-up event, the event confirmation of the fire telephone main unit is completed; When the call ends, the fire telephone main unit stops detecting the change in the bus current, and the fire telephone extension stops detecting the change in the bus voltage.

8. The fire communication method based on two-wire capacitive load switching logic judgment according to claim 6, wherein, In S4, for a single call, when the fire telephone extension calls the main unit, the fire telephone main unit / extension is powered for communication under voltage A. After the fire telephone main unit is connected, the communication handshake between the fire telephone main unit / extension is successful; the fire telephone main unit switches the voltage to output voltage B, and the fire telephone extension cuts off the energy storage electrolytic capacitor branch; The call loop of the fire telephone main / extension is connected to establish a call; the fire telephone main unit samples the bus current under voltage B in real time, and the fire telephone extension samples the bus voltage in real time; The fire telephone main unit hangs up the call / closes the call loop; the fire telephone main unit switches to voltage A, the fire telephone extension detects the bus pressure difference ΔU, reconnects the energy storage electrolytic to the branch, and closes the call loop; the fire telephone main unit communicates and issues a hang-up event, and the fire telephone extension completes the event confirmation; After the call ends, the fire telephone main unit stops detecting the change of the bus current, and the fire telephone extension stops detecting the change of the bus voltage.

9. The fire communication method based on the two-wire capacitive load switching logic judgment according to claim 6, wherein In S4, for multiple calls, if the fire telephone main unit calls the extension, the fire telephone main unit closes the call loop and switches to voltage A. The fire telephone extension detects the bus pressure difference ΔU. When the extension in the call closes the call loop, all the extensions on the line reconnect the energy storage electrolytic to the branch; the fire telephone main unit communicates and issues an event, all the extensions on the line cut off the energy storage electrolytic branch, and all the extensions that have established a call reconnect to the call loop; the fire telephone main unit switches to voltage B and connects the call loop; If the called fire telephone extension connects to the call branch, the fire telephone main unit samples and detects the change of the bus current of voltage B. The fire telephone main unit closes the call loop and switches to voltage A; the fire telephone extension detects the bus pressure difference U. When the extension in the call closes the call loop, all the extensions on the line reconnect the energy storage electrolytic to the branch. The fire telephone extension receives the inspection frame and reports the connection event, and the fire telephone main unit completes the event confirmation; the fire telephone main / extension confirms the establishment of the call; All the extensions on the line cut off the energy storage electrolytic branch, and all the extensions that have established a call reconnect to the call loop; the fire telephone main unit switches to voltage B and connects the call loop; If the fire telephone main unit hangs up the call, the fire telephone main unit closes the call loop and switches to voltage A. The fire telephone extension detects the bus pressure difference ΔU and reconnects the energy storage electrolytic to the branch; the fire telephone main unit communicates and issues a hang-up event, and the fire telephone extension completes the event confirmation and closes the call loop; the fire telephone main / extension cancels the establishment of the call, and the main unit confirms whether there are other extensions establishing a call; All the extensions on the line cut off the energy storage electrolytic branch, and all the extensions that have established a call reconnect to the call loop; the fire telephone main unit switches to voltage B and connects the call loop.

10. The fire communication method based on the two-wire capacitive load switching logic judgment according to claim 6, characterized in that, In S4, for multiple calls, if the fire telephone extension calls the main unit, the fire telephone extension connects to the call branch, and the fire telephone main unit samples and detects the change of the bus current of source B; the fire telephone main unit closes the call loop and switches to voltage A; The fire telephone extension detects the bus pressure difference ΔU. When the extension in the call closes the call loop, all the extensions on the line reconnect the energy storage electrolytic to the branch; The fire telephone extension receives the inspection frame and reports the call event, and the fire telephone main unit completes the event confirmation and issues the event; All the extensions on the line cut off the energy storage electrolytic branch, and all the extensions that have established a call reconnect to the call loop; the fire telephone main unit switches to voltage B and connects the call loop; When the fire telephone host presses a button to connect a call, the fire telephone main unit closes the call loop and the fire telephone main unit switches to voltage A; the fire telephone extension detects the bus voltage difference ΔU, and when the extension in the call state closes the call loop, all extensions on the line reconnect the energy storage electrolytic capacitor to the branch; the fire telephone host communicates and issues a connection event, and the fire telephone extension confirms the event; The fire telephone main / extension confirms the establishment of a call; All extensions on the line cut off the energy storage electrolytic capacitor branch, and all extensions that have established a call reconnect to the call loop; the fire telephone main unit switches to voltage B to connect the call loop; When the fire telephone extension hangs up the call, the fire telephone extension closes the call loop, and the fire telephone main unit detects the change in the bus current of voltage B; the fire telephone main unit closes the call loop, and the fire telephone main unit switches to voltage A; the fire telephone extension detects the bus voltage difference AU, and when the extension in the call state closes the call loop, all extensions on the line reconnect the energy storage electrolytic capacitor to the branch; the fire telephone extension receives the inspection frame and reports a hang-up event, and the fire telephone main unit confirms the event; The fire telephone main / extension cancels the establishment of a call, and the main unit confirms whether there are other extensions establishing a call; All extensions on the line cut off the energy storage electrolytic capacitor branch, and all extensions that have established a call reconnect to the call loop; the fire telephone main unit switches to voltage B to connect the call loop.

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