High-reliability two-bus loop communication system and method

Abstract

The application discloses a high-reliability two-bus loop communication system and method, and applies to the technical field of fire alarm.The system comprises a fire alarm controller and a plurality of communication units.The fire alarm controller comprises a main control board, an information output unit, a key input unit, a control output unit, a power supply and a loop card.The information output unit, the key input unit, the control output unit, the power supply and the loop card are connected with the main control board.A left communication port and a right communication port are arranged in the loop card.Two buses are connected in a loop mode at the left communication port and the right communication port.The communication units are connected on the two buses.A short-circuit isolator is arranged in the communication unit.The application adopts loop communication.When single-point short-circuit or open-circuit occurs at any point on the two-bus loop, all the communication units do not lose, and the reliability of the two-bus working of the fire alarm is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of fire alarm technology, and more specifically to a highly reliable two-bus loop communication system and method. Background Technology

[0002] In automatic fire alarm and linkage systems, two-wire technology is commonly used. Two-wire refers to two lines that can both supply power and communicate, enabling bidirectional signal transmission. The communication principle is as follows: the fire alarm controller acts as the transmitting end, typically a loop card installed within the controller, serially outputting the required commands and data to the two-wire line via carrier waves. The receiving end consists of communication units on the two-wire line, typically detectors, manual alarm buttons, input / output modules, etc., installed in the field. These units receive power from the bus and can also receive commands from the loop card and send response data back to the loop card. This fulfills the requirement of sharing a bus for both power supply and signal transmission. In existing two-wire communication schemes, with single-ended power supply communication, if an open circuit occurs on the two-wire line, all units after the open circuit point will be lost; if a short circuit occurs, all units on the entire bus will be lost. With dual-ended power supply communication technology, a single-point open circuit on the bus can be switched to dual-ended power supply without losing units, but a short circuit on both buses will result in the loss of all units. Based on dual-ended power supply communication technology, several short-circuit isolators are inserted into the bus. When a short circuit occurs at a point on the bus, the two adjacent short-circuit isolators will disconnect, thus the unit between the two short-circuit isolators will be lost, while the other units can continue to operate through two-way power supply and communication.

[0003] In summary, existing two-bus automatic fire alarm technology inevitably results in some unit loss during short circuits, failing to achieve completely loss-free operation. Furthermore, it increases power consumption when dealing with long lines and a large number of units. Therefore, providing a highly reliable two-bus loop communication system and method is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides a highly reliable two-bus loop communication system and method. When a circuit break or short circuit occurs at a certain point on the loop two-bus, the loop card will switch the communication mode, which can ensure that no communication unit is lost.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A highly reliable two-bus loop communication system includes a fire alarm controller and multiple communication units. The fire alarm controller includes a main control board, an information output unit, a key input unit, a control output unit, a power supply, and a loop card. The information output unit, key input unit, control output unit, power supply, and loop card are all connected to the main control board. The loop card is equipped with a left communication port, a right communication port, and a port voltage detection circuit. The two buses are connected in a loop to the left and right communication ports. The communication units are connected to the two buses, and each communication unit is equipped with a bidirectional short-circuit isolator.

[0007] Optionally, the loop card also includes a power supply and communication function module, a control function module, and a bus switching circuit. The bus switching circuit is used to switch the communication ports of the loop card. The power supply and communication function module is connected to the left communication port and the right communication port, and the control function module is connected to the left communication port and the right communication port.

[0008] Optionally, the bidirectional short-circuit isolator in the communication unit includes an MCU circuit, a left-side switch Q1, and a right-side switch Q2.

[0009] Optionally, the communication methods of the loopback card include left-port communication, right-port communication, and dual-port communication.

[0010] Optionally, the communication unit may also include a call direction detection circuit.

[0011] Optionally, the communication unit can be one of a fire detector, a manual button, or an input / output module.

[0012] A highly reliable two-bus loop communication method, applying any one of the above-described highly reliable two-bus loop communication systems, includes the following steps:

[0013] S1, the voltage of the left and right communication ports of the loop card;

[0014] S2. Determine the fault type based on the port voltage detection results;

[0015] S3. When the fault type is short circuit, proceed to S4; when the fault type is open circuit, proceed to S5.

[0016] S4. The loop card switches from left port communication to right port communication and detects the voltage of the right communication port. Based on the detection result, it determines the short circuit point and switches the communication port. It then sequentially closes the bidirectional short circuit isolators in the communication unit along the communication port until the short circuit point is isolated.

[0017] S5. The loop card switches from left-port communication to dual-port communication, starting from the first communication unit connected to the right port and sequentially closing the bidirectional short-circuit isolators until the communication unit next to the disconnected line.

[0018] As can be seen from the above technical solution, compared with the prior art, the present invention provides a highly reliable two-bus loop communication system and method, which has the following beneficial effects: The present invention sets up dual ports for communication in the loop card and sets up a bidirectional short-circuit isolator in the communication unit. When a single point of open circuit occurs on the bus, it can switch to dual-end power supply. When a single point of short circuit occurs on the bus, the bidirectional short-circuit isolator can isolate the short-circuit part. Therefore, when a single point of short circuit or open circuit occurs at any point on the two-bus loop, all communication units are not lost. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the two-bus loop communication system of the present invention;

[0021] Figure 2 A schematic diagram of a prior art two-bus single-ended power supply communication system;

[0022] Figure 3 This is a schematic diagram of the loop card of the present invention;

[0023] Figure 4 This is a schematic diagram of the communication unit isolator of the present invention;

[0024] Figure 5 This is a schematic diagram of the loop card port voltage detection circuit in an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the incoming call direction detection circuit of the communication unit in an embodiment of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] This invention discloses a highly reliable two-bus loop communication system, such as... Figure 1As shown, the device includes a fire alarm controller and multiple communication units. The fire alarm controller includes a main control board, an information output unit, a key input unit, a control output unit, a power supply, and a loop card. The information output unit, key input unit, control output unit, power supply, and loop card are all connected to the main control board. The loop card is equipped with a left communication port, a right communication port, and a port voltage detection circuit. Two buses are connected to the left and right communication ports in a ring configuration. The communication units are connected to the two buses, and each communication unit is equipped with a bidirectional short-circuit isolator.

[0028] Existing two-bus single-ended power supply communication systems, such as Figure 2 As shown, if an open circuit occurs on the two-wire bus, all cells after the open circuit point will be lost; if a short circuit occurs on the two-wire bus, all cells on the entire bus will be lost.

[0029] Furthermore, such as Figure 3 As shown, the loop card also includes a power supply and communication function module, a control function module, and a bus switching circuit. The bus switching circuit is used to switch the communication ports of the loop card. The power supply and communication function module is connected to the left communication port and the right communication port, and the control function module is connected to the left communication port and the right communication port.

[0030] Furthermore, in one embodiment of the present invention, such as Figure 5 As shown, both the left and right communication ports of the loop card are equipped with port voltage detection circuits. The port voltage detection circuits use differential amplification to convert the voltage on the left and right communication ports into a verified level and send it to the ADC port of the MCU. By detecting the ADC level, the voltage of the left and right communication ports can be known. When a short circuit occurs initially, both the left and right communication ports will detect a low voltage, and the short circuit isolation procedure can be started.

[0031] Furthermore, such as Figure 4 As shown, the bidirectional short-circuit isolator in the communication unit includes an MCU circuit, a left switch Q1, and a right switch Q2;

[0032] Furthermore, in this embodiment of the invention, when the gate of Q1 is at a low level, the left-end line can be disconnected, and when the gate of Q1 is at a high level, the left-end line can be connected; the same applies to Q2.

[0033] Furthermore, the communication methods of the loopback card include left-port communication, right-port communication, and dual-port communication.

[0034] Furthermore, the communication unit is also equipped with a call direction detection circuit.

[0035] like Figure 6As shown, when the MCU's PO pin is set to a high level, the level of the PI pin can be read to determine the direction of the incoming call. When the PI pin is low, the call is coming from the left, and when the PI pin is high, the call is coming from the right.

[0036] Furthermore, the communication unit is one of the following: fire detector, manual button, or input / output module.

[0037] and Figure 1 Corresponding to the aforementioned system, this embodiment of the invention also discloses a highly reliable two-bus loop communication method. Applying any of the above-described highly reliable two-bus loop communication systems includes the following steps:

[0038] S1, the voltage of the left and right communication ports of the loop card;

[0039] S2. Determine the fault type based on the port voltage detection results;

[0040] S3. When the fault type is short circuit, proceed to S4; when the fault type is open circuit, proceed to S5.

[0041] S4. The loop card switches from left port communication to right port communication and detects the voltage of the right communication port. Based on the detection result, it determines the short circuit point and switches the communication port. It then sequentially closes the bidirectional short circuit isolators in the communication unit along the communication port until the short circuit point is isolated.

[0042] S5. The loop card switches from left-port communication to dual-port communication, starting from the first communication unit connected to the right port and sequentially closing the bidirectional short-circuit isolators until the communication unit next to the disconnected line.

[0043] In one embodiment of the present invention, a short circuit occurs at the root of the left communication port of the loop card connected to the two buses. At this time, both the left and right communication ports of the loop card detect low port voltages simultaneously, switching from left port communication to right port communication, and performing a voltage check on the right communication port. If the voltage of the right communication port is normal, it indicates that the fault does not occur at the root of the right communication port. The left communication port is then attempted to be closed again, and its voltage is checked. Because the root of the left communication port is short-circuited, the left communication port immediately detects a low voltage and immediately disconnects, keeping the right communication port closed. All communication units detect a low bus voltage and immediately disconnect the bidirectional short-circuit isolator, isolating the short circuit. At this time, the first communication unit on the right communication port detects that the bus voltage has returned to normal and begins to attempt to close the bidirectional short-circuit isolator. After closing, it finds that the bus voltage is still normal and maintains it. Then, the second communication unit on the right communication port detects that the bus voltage has returned to normal and begins to attempt to close the bidirectional short-circuit isolator. This continues one after another until the first communication unit on the left communication port closes the bidirectional short-circuit isolator. This unit immediately detects a low bus voltage after closing the bidirectional short-circuit isolator and immediately disconnects the left bidirectional short-circuit isolator, closing only the right bidirectional short-circuit isolator. This achieves short-circuit isolation at the root of the left communication port.

[0044] In one embodiment of the present invention, a short circuit occurs at the root of the right communication port of the loop card connected to the two buses. At this time, both the left and right communication ports of the loop card simultaneously detect low port voltage. The loop card immediately switches to right port communication and performs right communication port voltage detection. Because the root of the right communication port is short-circuited, the right communication port immediately detects low voltage, indicating that the short circuit fault occurs at the root of the right communication port. The right communication port is immediately disconnected, and then the left communication port is attempted to be closed and its voltage is detected. The left communication port voltage is normal, so the left communication port remains closed. All communication units detect low bus voltage and immediately disconnect the bidirectional short-circuit isolators, isolating the short circuit. At this time, the first communication unit of the left communication port detects that the bus voltage has returned to normal and begins to attempt to close the bidirectional short-circuit isolators. After closing, it finds that the bus voltage is still normal and remains so. At this time, the second communication unit of the left communication port detects that the bus voltage has returned to normal and begins to attempt to close the bidirectional short-circuit isolators. This continues one after another until the first communication unit of the right communication port closes the bidirectional short-circuit isolators. After this unit closes the bidirectional short-circuit isolators, it immediately finds that the bus voltage has become low and immediately disconnects the right bidirectional short-circuit isolators, closing only the left bidirectional short-circuit isolators. This achieves short-circuit isolation at the root of the right communication port.

[0045] In one embodiment of the invention, when a short circuit occurs on a segment of the loop-two bus, and this segment is neither at the root of the left port nor the root of the right port of the loop card, both the left and right communication ports of the loop card simultaneously detect low port voltage. The loop card immediately switches to right port communication and performs a voltage check on the right communication port. The right communication port immediately detects a normal voltage and then attempts to close the left communication port and checks its voltage. The left communication port voltage is normal, thus maintaining both ports closed. All communication units detect a low bus voltage and immediately disconnect the bidirectional short-circuit isolator, isolating the short circuit. At this point, the first communication unit on the left communication port detects that the bus voltage has returned to normal and attempts to close the isolator. After closing, it finds that the bus voltage is still normal and maintains this state. Then, the second communication unit on the left communication port detects that the bus voltage has returned to normal and begins to attempt to close the isolator. This continues one after another until the communication unit next to the short-circuit segment closes its isolator. After this unit closes its isolator, it immediately finds that the bus voltage has dropped and immediately disconnects the right isolator, closing only the left isolator. Simultaneously, the first communication unit on the right communication port detects that the bus voltage has returned to normal and attempts to close the isolator. After closing, it finds that the bus voltage is still normal and maintains this state. Then, the second communication unit on the right communication port detects that the bus voltage has returned to normal and begins to attempt to close the isolator. This continues one after another until the communication unit next to the short-circuit segment closes its isolator. After this unit closes its isolator, it immediately finds that the bus voltage has dropped and immediately disconnects the left isolator, closing only the right isolator. This achieves short-circuit isolation for non-root sections.

[0046] In one embodiment of the invention, a section of the loop-two bus experiences a break in voltage. The left communication port of the loop card detects normal voltage, while the right communication port detects low voltage, indicating a break in the loop-two bus. The loop card immediately switches to dual-port communication. The communication unit to the right of the break point on the loop-two bus detects low bus voltage and immediately disconnects the left and right isolators. At this time, the first communication unit on the right communication port detects that the bus voltage has returned to normal and attempts to close the isolator. After closing, it finds that the bus voltage is still normal and maintains it. Then, the second communication unit on the right communication port detects that the bus voltage has returned to normal and attempts to close the isolator. This continues one after another until the communication unit next to the broken section closes the isolator and finds that the bus voltage is normal. At this point, all communication units are connected to the loop card again.

[0047] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0048] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A highly reliable two-bus loop communication system, characterized in that, It includes a fire alarm controller and multiple communication units. The fire alarm controller includes a main control board, an information output unit, a key input unit, a control output unit, a power supply, and a loop card. The information output unit, key input unit, control output unit, power supply, and loop card are all connected to the main control board. The loop card is equipped with a left communication port, a right communication port, and a port voltage detection circuit. Two buses are connected to the left and right communication ports in a ring manner. The communication unit is connected to the two buses and is equipped with a bidirectional short-circuit isolator. The loop card also includes a power supply and communication function module, a control function module, and a bus switching circuit. The bus switching circuit is used to switch the communication port of the loop card. The power supply and communication function module is connected to the left communication port and the right communication port, and the control function module is connected to the left communication port and the right communication port. The bidirectional short-circuit isolator in the communication unit includes an MCU circuit, a left-side switch Q1, and a right-side switch Q2; The communication methods of the loopback card include left-port communication, right-port communication, and dual-port communication; The communication unit is also equipped with a circuit for detecting the direction of incoming calls.

2. The high-reliability two-bus loop communication system according to claim 1, characterized in that, The communication unit is one of the following: fire detector, manual button, or input / output module.

3. A highly reliable two-bus loop communication method, characterized in that, The application of a high-reliability two-bus loop communication system according to any one of claims 1-2 includes the following steps: S1, the voltage of the left and right communication ports of the loop card; S2. Determine the fault type based on the port voltage detection results; S3. When the fault type is short circuit, proceed to S4; when the fault type is open circuit, proceed to S5. S4. The loop card switches from left port communication to right port communication and detects the voltage of the right communication port. Based on the detection result, it determines the short circuit point and switches the communication port. It then sequentially closes the bidirectional short circuit isolators in the communication unit along the communication port until the short circuit point is isolated. S5. The loop card switches from left-port communication to dual-port communication, starting from the first communication unit connected to the right port and sequentially closing the bidirectional short-circuit isolators until the communication unit next to the disconnected line.

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