High-reliability two-bus loop communication system and method

Abstract

The invention discloses a high-reliability two-bus loop communication system and a high-reliability two-bus loop communication method, which are applied 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, and the information output unit, the key input unit, the control output unit, the power supply and the loop card are all connected with the main control board. A left communication port and a right communication port are arranged in the loop card, the two buses are connected to the left communication port and the right communication port in an annular mode, the communication unit is connected to the two buses, and a short circuit isolator is arranged in the communication unit. Loop communication is adopted, when single-point short circuit or open circuit occurs at any point on the two-bus loop, all communication units are not lost, and the working reliability of the fire alarm two-bus is greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of fire alarm technology, and more particularly to a high-reliability two-bus loop communication system and method. Background Art

[0002] In the fire automatic alarm and linkage system, the two-bus technology is usually used. The two-bus refers to two lines that can both supply power and communicate, realizing two-way transmission of signals. The communication principle is: the fire alarm controller is the sending end, which is generally a loop card installed in the fire alarm controller, and the instructions and data to be transmitted are serially output to the two-bus in the form of a carrier. The receiving end is the communication unit on the two-bus, which is generally a detector, manual alarm button, input and output module, etc. installed on the site. While receiving power from the bus, it can also receive commands sent by the loop card and send response data to the loop card. In this way, the requirements of sharing the bus for power supply and signal are met. In the existing two-bus communication scheme, when the two-bus single-end power supply communication is used, if a circuit break occurs on the two-bus, all units after the circuit break point will be lost; if a short circuit occurs on the two-bus, all units on the entire bus will be lost; in the two-bus double-end power supply communication technology, if a single-point circuit break occurs on the bus, it can be switched to double-end power supply, and no unit will be lost, but if a short circuit occurs on the two buses, all units will be lost. On the basis of the two-bus double-end power supply communication technology, several short-circuit isolators are inserted on the bus. When a short circuit occurs at a certain point on the bus, the two adjacent short-circuit isolators will be disconnected, so that the unit between the two short-circuit isolators will be lost, and the remaining units can continue to work through double-ended power supply communication.

[0003] In summary, the existing fire automatic alarm two-bus technology will always lose units when a short circuit occurs, and it is impossible to achieve complete zero loss. In addition, the power consumption of the bus will increase in the case of long lines and a large number of units. Therefore, how to provide a highly reliable two-bus loop communication system and method is an urgent problem 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 break or short circuit occurs at a certain point on the loop two bus, the loop card will switch the communication mode to ensure that no communication unit is lost.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A high-reliability 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, the key input unit, the control output unit, the power supply and the loop card are all connected to the main control board. A left communication port, a right communication port and a port voltage detection circuit are arranged in the loop card. Two buses are connected to the left communication port and the right communication port in a ring manner. The communication unit is connected to the two buses. A two-way short-circuit isolator is arranged in the communication unit.

[0007] Optionally, the loop card also includes a power supply 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 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 switch Q1 and a right switch Q2.

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

[0010] Optionally, a call direction detection circuit is also provided in the communication unit.

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

[0012] A high-reliability two-bus loop communication method, using any one of the high-reliability two-bus loop communication systems described above, comprises the following steps:

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

[0014] S2. determining the fault type based on the detection result of the port voltage;

[0015] S3, when the fault type is short circuit, enter S4, when the fault type is open circuit, enter S5;

[0016] S4, the loop card switches from left port communication to right port communication and detects the voltage of the right communication port, determines the short circuit occurrence point based on the detection result and switches the communication port, and sequentially closes the bidirectional short circuit isolators in the communication unit along the communication ports until the short circuit occurrence point is isolated;

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

[0018] It can be seen from the above technical solution that 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 dual ports on the loop card for communication and sets a two-way short-circuit isolator in the communication unit. When a single-point break occurs on the bus, it can be switched to two-end power supply. When a single-point short circuit occurs on the bus, the two-way short-circuit isolator can isolate the short-circuited part. Therefore, when a single-point short circuit or break occurs at any point on the two-bus loop, all communication units are not lost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

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

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

[0022] Figure 3 It is a schematic diagram of a circuit card of the present invention;

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

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

[0025] Figure 6 Schematic diagram of a communication unit incoming call direction detection circuit in an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The embodiment of the present invention discloses a high reliability two-bus loop communication system, such as Figure 1As shown, 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, the key input unit, the control output unit, the power supply and the loop card are all connected to the main control board. A left communication port, a right communication port and a port voltage detection circuit are arranged in the loop card. Two buses are connected to the left communication port and the right communication port in a ring manner. The communication unit is connected to the two buses. A bidirectional short-circuit isolator is arranged in the communication unit.

[0028] The two-bus single-ended power supply communication system in the prior art is as follows: Figure 2 As shown, if a break occurs on the second bus, all units after the break point will be lost; if a short circuit occurs on the second bus, all units on the entire bus will be lost.

[0029] Further, such as Figure 3 As shown, the loop card also includes a power supply 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 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, Figure 5 As shown, the left communication port and the right communication port of the loop card are both provided with a port voltage detection circuit. The port voltage detection circuit converts the voltage on the left communication port and the right communication port into a verified level by differential amplification and sends it to the ADC port of the MCU. By detecting the ADC level, the voltage of the left communication port and the right communication port can be known. When a short circuit occurs at the beginning, both the left communication port and the right communication port will detect a low voltage, and the short circuit isolation procedure can be started.

[0031] Further, 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 the embodiment of the present 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 modes of the loop card include left-port communication, right-port communication and dual-port communication.

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

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

[0036] Furthermore, the communication unit is one of a fire detector, a manual button, and an input / output module.

[0037] and Figure 1 Corresponding to the system, an embodiment of the present invention further discloses a high-reliability two-bus loop communication method, which uses any one of the high-reliability two-bus loop communication systems described above, and includes the following steps:

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

[0039] S2. determining the fault type based on the detection result of the port voltage;

[0040] S3, when the fault type is short circuit, enter S4, when the fault type is open circuit, enter S5;

[0041] S4, the loop card switches from left port communication to right port communication and detects the voltage of the right communication port, determines the short circuit occurrence point based on the detection result and switches the communication port, and sequentially closes the bidirectional short circuit isolators in the communication unit along the communication ports until the short circuit occurrence point is isolated;

[0042] S5. The loop card switches from left-port communication to dual-port communication, and sequentially closes the bidirectional short-circuit isolators starting from the first communication unit connected to the right port 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, the left communication port and the right communication port of the loop card simultaneously detect that the port voltage is low, and the communication is switched from the left port to the right port, and the voltage of the right communication port is detected. If the voltage of the right communication port is normal, it means that the fault did not occur at the root of the right communication port; try to close the left communication port again and detect the voltage of the left communication port. Because the root of the left communication port is short-circuited, the left communication port immediately detects the low voltage, and the left communication port is immediately disconnected, and the right communication port is kept closed. All communication units detect that the bus voltage is low, and immediately disconnect the bidirectional short-circuit isolator, and the short circuit is isolated. At this time, the first communication unit of the right communication port detects that the bus voltage has returned to normal and starts to try to close the bidirectional short-circuit isolator. After closing, it is found that the bus voltage is still normal and it is kept. At this time, the second communication unit of the right communication port detects that the bus voltage has returned to normal and starts to try to close the bidirectional short-circuit isolator, one after another until the first communication unit of the left communication port, this unit immediately finds that the bus voltage becomes low after closing the bidirectional short-circuit isolator, and immediately disconnects the left bidirectional short-circuit isolator and only closes 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, the left and right communication ports of the loop card simultaneously detect low port voltages. The loop card immediately switches to right port communication and performs voltage detection on the right communication port. 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 tried to be closed and the voltage of the left communication port is detected. The voltage of the left communication port is normal, and the left communication port is kept closed. All communication units detect that the bus voltage is low, and the bidirectional short-circuit isolator is immediately disconnected, and the short circuit is isolated. At this time, the first communication unit of the left communication port detects that the bus voltage has returned to normal and starts to try to close the bidirectional short-circuit isolator. After closing, it is found that the bus voltage is still normal and it is maintained. At this time, the second communication unit of the left communication port detects that the bus voltage has returned to normal and starts to try to close the bidirectional short-circuit isolator, one after another until the first communication unit of the right communication port. After this unit closes the bidirectional short-circuit isolator, it immediately finds that the bus voltage becomes low, and immediately disconnects the right bidirectional short-circuit isolator, and only closes the left bidirectional short-circuit isolator. This achieves short-circuit isolation at the root of the right communication port.

[0045] In one embodiment of the present invention, when a line segment on the loop bus 2 is short-circuited and the segment is not at the root of the left port of the loop card, nor at the root of the right port of the loop card, the left communication port and the right communication port of the loop card simultaneously detect low port voltages, and the loop card immediately switches to right port communication and performs voltage detection on the right communication port. The right communication port immediately detects that the voltage is normal, and then tries to close the left communication port and detect the voltage of the left communication port. The voltage of the left communication port is normal, and thus the two ports are kept closed. When all communication units detect that the bus voltage is low, they immediately disconnect the bidirectional short-circuit isolator, and the short circuit is isolated. At this time, the first communication unit of the left communication port detects that the bus voltage has returned to normal and starts to try to close the isolator. After closing, it finds that the bus voltage is still normal and keeps it. At this time, the second communication unit of the left communication port checks that the bus voltage has returned to normal and starts to try to close the isolator. This continues until the communication unit next to the short-circuit section. This unit immediately finds that the bus voltage has become low after closing the isolator, and immediately disconnects the right isolator and only closes the left isolator. At the same time, the first communication unit of the right communication port detects that the bus voltage has returned to normal and starts to try to close the isolator. After closing, it finds that the bus voltage is still normal and keeps it. At this time, the second communication unit of the right communication port checks that the bus voltage has returned to normal and starts to try to close the isolator. This continues until the communication unit next to the short-circuit section. This unit immediately finds that the bus voltage has become low after closing the isolator, and immediately disconnects the left isolator and only closes the right isolator. In this way, non-root short-circuit isolation is achieved.

[0046] In one embodiment of the present invention, a line on the loop 2 bus is disconnected, the left communication port of the loop card detects that the voltage is normal, and the right communication port detects that the port voltage is low, so it can be determined that a circuit break has occurred on the loop 2 bus. The loop card immediately switches to dual-port communication. The communication unit on the right side of the loop 2 bus disconnection point detects that the bus voltage is low 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 starts to try to close the isolator. After closing, it is found that the bus voltage is still normal and it is maintained. At this time, the second communication unit on the right communication port detects that the bus voltage has returned to normal and starts to try to close the isolator, one after another until the communication unit next to the disconnected line segment, this unit closes the isolator and finds that the bus voltage is normal, and at this time all the communication units are connected to the loop card again.

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

[0048] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one 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 present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high reliability 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, the key input unit, the control output unit, the power supply and the loop card are all connected to the main control board. A left communication port, a right communication port and a port voltage detection circuit are arranged in the loop card. Two buses are connected to the left communication port and the right communication port in a ring manner. The communication unit is connected to the two buses. A bidirectional short-circuit isolator is arranged in the communication unit.

2. A high reliability two-bus loop communication system according to claim 1, characterized in that: The loop card also includes a power supply 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 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.

3. A high reliability two-bus loop communication system according to claim 2, characterized in that: The bidirectional short-circuit isolator in the communication unit includes the MCU circuit, the left switch Q1 and the right switch Q2 。 4. A high reliability two-bus loop communication system according to claim 2, characterized in that: The communication modes of the loop card include left port communication, right port communication and dual port communication.

5. A high reliability two-bus loop communication system according to claim 1, characterized in that: The communication unit is also provided with an incoming call direction detection circuit.

6. A high reliability two-bus loop communication system according to claim 1, characterized in that: The communication unit is one of a fire detector, a manual button, and an input-output module.

7. A high reliability two-bus loop communication method, characterized in that: A high reliability two-bus loop communication system according to any one of claims 1 to 6 is applied, comprising the following steps: S1, the left communication port and the right communication port of the loop card detect the port voltage; S2. determining the fault type based on the detection result of the port voltage; S3, when the fault type is short circuit, enter S4, when the fault type is open circuit, enter S5; S4, the loop card switches from left port communication to right port communication and detects the voltage of the right communication port, determines the short circuit occurrence point based on the detection result and switches the communication port, and sequentially closes the bidirectional short circuit isolators in the communication unit along the communication ports until the short circuit occurrence point is isolated; S5. The loop card switches from left-port communication to dual-port communication, and sequentially closes the bidirectional short-circuit isolators starting from the first communication unit connected to the right port until the communication unit next to the disconnected line.

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