Non-carrier three-state two-bus communication method and system

Abstract

The invention relates to a non-carrier three-state two-bus communication method and system, and belongs to the technical field of communication. The bus voltage logic state is adjusted to be a power supply state, a communication state and an idle state, the bus supplies power to the child nodes in the power supply state, communication between the main node and the child nodes is carried out in the communication state, and communication and power supply are achieved by switching the power supply state, the communication state and the idle state through the bus. Time-sharing work of power supply and communication of each node is achieved through switching of each state of the two buses, high reliability of wired transmission is achieved, and wire materials and construction cost are reduced.

Description

Technical Field

[0001] The invention relates to a non-carrier three-state two-bus communication method and system, belonging to the technical field of communication. Background Art

[0002] Compared with the four-wire system, the two-bus system combines the power line and the signal line into one, realizing the technology of sharing the same bus for signal and power supply. The two-bus wiring has no polarity requirement, which brings great convenience to on-site construction and later maintenance, and saves construction and cable costs. It is widely used in fire protection, instrumentation, sensors, digital electronic detonators, industrial control and other fields.

[0003] At present, the two-bus communication mainly adopts the communication method of downlink voltage signal and uplink current signal. The sampling resistance on the bus is made small, and then it is amplified and analyzed. This method solves the problem of excessive bus voltage drop when the load current increases, but the process is a dynamic change process. As a result, the change in feedback current and the change in node power consumption current offset each other, and the current change on the controller sampling resistor is small and not smooth, which makes data decoding very difficult. As the number of nodes increases, decoding may even be impossible. Summary of the invention

[0004] The purpose of the present invention is to provide a non-carrier three-state two-bus communication method and system to solve the problem of low communication efficiency in the current communication process.

[0005] In order to solve the above technical problems, the present invention provides a non-carrier three-state two-bus communication method, which comprises the following steps:

[0006] 1) Connecting the master node and the sub-nodes via a non-carrier three-state two-bus to form a corresponding network;

[0007] The non-carrier three-state two-bus includes a power supply state, a communication state and an idle state. When the bus is in the power supply state, it is used to supply power to all sub-nodes. When it is in the communication state, it is responsible for communication between the master node and the sub-nodes. When it is in the idle state, it is responsible for reporting data applications by the sub-nodes.

[0008] 2) The master node is used to switch the bus from the power state to the idle state at a set frequency, so that the child node can report data requests by applying for interrupts. When the child node applies for interrupts, the master node switches the bus from the idle state to the communication state, and in the communication state, commands the child node to report data through the bus. After the reporting is completed, the master node switches the bus to the power state.

[0009] The present invention adjusts the bus voltage logic state into a power supply state, a communication state and an idle state, so that the bus supplies power to the sub-node in the power supply state, and communicates between the main node and the sub-node in the communication state, and realizes communication and power supply by switching the power supply state, the communication state and the idle state of the bus. The present invention realizes the time-sharing work of power supply and communication of each node by switching the states of the two buses, achieves high reliability of wired transmission, and reduces the wire material and construction costs.

[0010] Furthermore, if the master node does not sense that a child node has requested an interrupt in the idle state, the master node switches the bus from the idle state to the power supply state.

[0011] The present invention can switch the bus from an idle state to a power supply state through a master node when the child node has no need to upload information, so as to realize timely switching to the power supply state when communication is not required.

[0012] Furthermore, when the master node needs to send information to the sub-node, the master node switches the bus from the power supply state to the communication state for communication, and after the communication is completed, the master node switches the bus from the communication state to the power supply state.

[0013] The present invention can directly switch the bus from the power supply state to the communication state for communication when the master node has a communication demand, thereby further improving the communication efficiency.

[0014] Furthermore, when multiple sub-nodes initiate interruption requests simultaneously in the idle state, a bus contention process is performed.

[0015] Furthermore, bus competition is divided into primary competition and secondary competition. The primary competition is carried out in the idle state, and the secondary competition is carried out in the communication state. When multiple sub-nodes in the idle state apply for interruption at the same time, it indicates that a primary competition conflict occurs. The master node switches the bus to the communication state and carries out secondary competition. The master node orders the sub-node that applies for interruption to generate a random number. The master node orders the node that generates a smaller random number to apply for interruption first, and interrupts the applications of other sub-nodes participating in the primary competition.

[0016] Furthermore, for a child node that fails in competition, the master node makes it restart competition from the first level.

[0017] The present invention avoids conflicts caused by simultaneous communication of multiple nodes by setting a competition mechanism.

[0018] Furthermore, the power supply state, the communication state and the idle state correspond to different voltage ranges, and when the master node switches the state of the bus, it does so by controlling the voltage range of the power supply to which it is connected.

[0019] The present invention realizes the division of different bus states by setting different voltage ranges, and can accurately realize the switching of different states.

[0020] Furthermore, each sub-node is provided with a power management module, which is connected to the bus. When the bus is in a power supply state, the power supply of each sub-node is obtained from the bus.

[0021] The present invention arranges a power supply module at each node, so that when the bus is switched to a non-powered state, each node can still work with power.

[0022] Furthermore, a sub-node conflict counting module is provided in the main node, and the sub-node conflict counting module includes a sampling resistor and a voltage sampling circuit, which is used to count the sub-nodes that apply for interruption when the bus is in a communication state; a constant current circuit is provided in the sub-node, which is used to connect the constant current circuit with the bus when the sub-node applies for interruption, so that a constant current flows through the sampling resistor of the main node to form a unit voltage, and the main node determines whether there is a sub-node applying for interruption and the number of sub-nodes applying based on the voltage drop measured by the voltage sampling circuit.

[0023] The present invention also provides a non-carrier three-state two-bus communication system, comprising a master node and a plurality of sub-nodes, characterized in that the master node and the sub-nodes adopt the above-mentioned non-carrier three-state two-bus communication method.

[0024] The present invention adjusts the bus voltage logic state into a power supply state, a communication state and an idle state, so that the bus supplies power to the sub-node in the power supply state, and communicates between the main node and the sub-node in the communication state, and realizes communication and power supply by switching the power supply state, the communication state and the idle state of the bus. The present invention realizes the time-sharing work of power supply and communication of each node by switching the states of the two buses, achieves high reliability of wired transmission, and reduces the wire material and construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a node connection diagram of the non-carrier three-state two-bus communication system of the present invention;

[0026] Figure 2 It is a three-state conversion logic diagram of the non-carrier three-state two-bus communication system of the present invention;

[0027] Figure 3 It is a three-state division diagram of the non-carrier three-state two-bus communication system of the present invention;

[0028] Figure 4 is a diagram of a three-state division example in an embodiment of the present invention;

[0029] Figure 5 It is a structural diagram of a master node device of a non-carrier three-state two-bus communication system of the present invention;

[0030] Figure 6 It is a sub-node device structure diagram of the non-carrier three-state two-bus communication system of the present invention;

[0031] Figure 7 It is a bus competition flow chart of the non-carrier three-state two-bus communication system of the present invention;

[0032] Figure 8 It is a schematic diagram of the principle of conflict counting in the non-carrier three-state two-bus communication system of the present invention. DETAILED DESCRIPTION

[0033] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0034] The present invention connects the master node and the sub-node through a non-carrier three-state two-bus to form a corresponding network; the master node is used to switch the bus from the power supply state to the idle state according to the set frequency, so that the sub-node can report the data application by applying for interruption. When the sub-node applies for interruption, the master node switches the bus from the idle state to the communication state, and in the communication state, commands the sub-node to report data through the bus, and after the reporting is completed, the master node switches the bus to the power supply state. The present invention adjusts the bus voltage logic state to the power supply state, the communication state and the idle state, so that the bus supplies power to the sub-node in the power supply state, and the communication state is used for communication between the master node and the sub-node, and the communication and power supply are realized by switching the bus between the power supply state, the communication state and the idle state.

[0035] Embodiment of a non-carrier three-state two-bus communication system

[0036] The present invention includes a main node device and multiple sub-node devices. The main node device and the sub-node devices form a network through a non-carrier three-state two-bus to perform power supply and communication. The main node device includes a voltage platform selection module, a data sending module, a data receiving module, a command processing module, a sub-node conflict counting module, a power management and power storage module; the sub-node device includes a voltage platform detection module, a data sending module, a data receiving module, an interrupt application module, and a voltage platform detection module; the voltage platform selection module controls the bus state so that the bus expresses a power supply state, a communication state, and an idle state. The power supply state is responsible for supplying power to all sub-nodes, and the communication state is responsible for supplying power to all sub-nodes. The communication state is responsible for the communication between the master node and the sub-node, and the idle state is responsible for the sub-node reporting data application; the bus starts in the power state and switches to the idle state at a certain rhythm. If the sub-node needs to communicate, when the voltage platform detection module detects that the bus is in the idle state, the sub-node interrupt application module reports the data application and applies for interruption. The command processing module switches the bus from the idle state to the communication state, and the sub-node data sending module sends data to the main node data receiving module; if the master node needs to communicate, the command processing module switches the bus from the power state to the communication state, and the master node data sending module sends data to the sub-node data receiving module. The following is an explanation with specific examples.

[0037] The three-state two-bus system includes a master node device and multiple sub-node devices connected through two power lines to form a network. The master node and sub-nodes can be connected in a tree or star shape, such as Figure 1 As shown, the bus is two power lines with no polarity distinction, which can provide power and communicate.

[0038] The voltage platform is adjusted by multiple switches to express three logical states, forming power supply state, communication state, and idle state. The power supply state is responsible for supplying power to all sub-nodes, the communication state is responsible for communication between the master node and the nodes, and the idle state is used for the sub-node to report data application. The three-state conversion logic of the system is as follows Figure 2 As shown, the three-state switching is controlled by the master node, starting from the power supply state; the master node switches the bus from the power supply state to the idle state according to a certain period. When the bus is in the idle state, if the child node has data to report to the master node, it responds by changing the level in the idle state in the idle state and applies for an interrupt. The master node switches the idle state to the communication state and commands the child node to report data. After the report is completed, the bus state switches to the power supply state. If there is no child node response in the idle state, it directly switches to the power supply state; 2. When the master node needs to control or query the child node, the bus is switched from the power supply state to the communication state, and then switched to the power supply state after the communication is completed.

[0039] The three-state level division is as follows Figure 3 As shown: three voltage amplitudes and two isolation areas are divided on the bus. The top voltage amplitude is the power supply state, the bottom voltage amplitude is the idle state, the middle voltage amplitude is the communication state, and there is a safety isolation area between the three voltage amplitudes.

[0040] The three-state division performed in this embodiment is as follows Figure 4 As shown, when the bus level amplitude is in the 0.7*VDD~1*VDD area, all nodes do not transmit information, only supply power; when the bus level amplitude is in the 0.3*VDD~0.6*VDD area, the bus is cut off from the power supply, and data communication is performed at this time, 0.6*VDD represents a high level, and 0.3VDD represents a low level; when the bus level amplitude is in the 0*VDD~0.2*VDD area, the bus is cut off from the power supply, and the master node uses the internal child node to apply for interrupt counting circuit. When there are 0 child nodes applying for interruption, it will switch to the power supply state, and when there are ≥1 child nodes applying for interruption, it will switch to the communication state. The master node and each child node are provided with a power supply module, which is connected to the bus and supplies power to each power supply module when the bus is in the power supply state.

[0041] like Figure 5As shown, the master node device includes a voltage platform selection module, a data sending module, a data receiving module, a sub-node conflict counting module, a command processing module, and a power storage module. The voltage platform selection module is used to control the bus state so that the bus expresses a power supply state, a communication state, and an idle state; the data sending module is used to send data to the sub-node. When data needs to be sent, the master node switches the bus state to a communication state, cuts off the voltage supply, and the power line of the bus becomes a data line. The bus node converts binary into high and low levels and sends them out, wherein j*VDD is a high level and k*VDD is a low level, and the sub-node converts high and low levels into binary numbers; the data receiving module is used to receive data sent by the sub-node. When data reception is required, the master node switches the bus state to a communication state, cuts off the voltage supply, and the power line of the bus becomes a data line. The high and low levels sent by the sub-node are converted into binary numbers, wherein j*VDD is a high level and k*VDD is a low level.

[0042] The subnode conflict counting module includes a sampling resistor R1 and a voltage sampling circuit, such as Figure 8 As shown, it is used to determine whether there is a sub-node applying for an interrupt and how many sub-nodes apply for an interrupt. A constant current circuit is set in the corresponding sub-node. When in an idle state, if a sub-node applies for an interrupt, the controllable switch is controlled to connect the constant current circuit of the sub-node to the bus through the corresponding rectifier circuit, then a voltage difference of R1*I is generated on the sampling resistor of the main node on the bus. If n nodes apply for an interrupt, a voltage difference of n*R1*I is generated. The main node determines whether there is a sub-node applying for an interrupt and how many sub-nodes apply for an interrupt through the voltage difference on the resistor; the data command processing module is used to control channel switching, data transmission and reception, and conflict resolution; the power management and power storage module is responsible for the power supply of the internal circuit and the bus voltage stability.

[0043] like Figure 6 As shown, the sub-node device includes a voltage platform detection module, a data sending module, a data receiving module, an interrupt application module, a power isolation and power management module. The voltage platform detection module is used to detect the state of the bus in the three states through the voltage amplitude on the bus, and provide it to the command processing module; the data sending module is used to send data to the main node; the data receiving module is used to receive data sent by the main node; the interrupt application module is used to drive the module to work when the bus is in an idle state and the sub-node needs to apply for an interrupt, so that the constant current circuit is connected to the bus, and the purpose of conflict counting is achieved through the sub-station conflict counting module of the main node; the power isolation is used to make the power line in the power supply state in the power supply state, and the power line in the non-power supply state cuts off the power supply for data line communication with high reliability. The power management module is used to output different voltages to power each circuit module of the sub-node product.

[0044] When multiple child nodes initiate interrupt requests at the same time, bus competition is carried out. The competition is divided into primary competition and secondary competition. Primary competition is carried out in the idle state, and secondary competition is carried out in the communication state. All child nodes first initiate interrupt requests from the primary competition. When the primary competition conflicts, the master node puts the bus into the communication state and conducts secondary competition. The master node issues instructions to the child nodes that have applied for interrupts to generate random numbers. Each child node starts counting according to the generated random numbers. The child nodes with smaller random numbers will apply for interrupts first. After receiving the interrupt, the master node immediately interrupts other nodes that continue to apply for interrupts. When only one interrupt is generated, it starts uploading data to complete the competition. The child nodes that fail in the secondary competition need to restart the competition from the primary competition. The bus competition process is as follows: Figure 7 shown.

[0045] Embodiment of non-carrier three-state two-bus communication method

[0046] The master node and the sub-nodes are connected through a non-carrier three-state two-bus to form a corresponding network; wherein the non-carrier three-state two-bus includes a power supply state, a communication state and an idle state. When the bus is in the power supply state, it is used to supply power to the master node and all sub-nodes, when it is in the communication state, it is responsible for the communication between the master node and the sub-nodes, and when it is in the idle state, it is responsible for the sub-nodes to report data applications; the master node is used to switch the bus from the power supply state to the idle state according to the set frequency, so that the sub-nodes can report data applications by applying for interrupts. When the sub-nodes apply for interrupts, the master node switches the bus from the idle state to the communication state, and in the communication state, commands the sub-nodes to report data through the bus, and after the reporting is completed, the master node switches the bus to the power supply state. The specific implementation of this method has been described in detail in the embodiment of the non-carrier three-state two-bus communication system, and will not be repeated here.

Claims

1. A non-carrier three-state two-bus communication method, characterized in that: The method comprises the following steps: 1) Connecting the master node and the sub-nodes via a non-carrier three-state two-bus to form a corresponding network; The non-carrier three-state two-bus includes a power supply state, a communication state and an idle state. When the bus is in the power supply state, it is used to supply power to all sub-nodes. When it is in the communication state, it is responsible for communication between the master node and the sub-nodes. When it is in the idle state, it is responsible for reporting data applications by the sub-nodes. 2) The master node is used to switch the bus from the power state to the idle state at a set frequency, so that the child node can report data requests by applying for interrupts. When the child node applies for interrupts, the master node switches the bus from the idle state to the communication state, and in the communication state, commands the child node to report data through the bus. After the reporting is completed, the master node switches the bus to the power state.

2. The non-carrier three-state two-bus communication method according to claim 1, characterized in that: If the master node does not sense that there is any interrupt request from the child node in the idle state, the master node switches the bus from the idle state to the power supply state.

3. The non-carrier three-state two-bus communication method according to claim 1, characterized in that: When the master node needs to send information to the sub-node, the master node switches the bus from the power supply state to the communication state for communication, and after the communication is completed, the master node switches the bus from the communication state to the power supply state.

4. The non-carrier three-state two-bus communication method according to claim 1, characterized in that: When multiple child nodes simultaneously initiate interrupt requests in the idle state, a bus contention process is performed.

5. The non-carrier three-state two-bus communication method according to claim 4, characterized in that: Bus competition is divided into primary competition and secondary competition. Primary competition is carried out in the idle state, and secondary competition is carried out in the communication state. When multiple sub-nodes in the idle state apply for interruption at the same time, it means that a primary competition conflict occurs. The master node switches the bus to the communication state and carries out secondary competition. The master node orders the sub-node that applies for interruption to generate a random number. The master node orders the node that generates a smaller random number to apply for interruption first, and interrupts the applications of other sub-nodes participating in the primary competition.

6. The non-carrier three-state two-bus communication method according to claim 5, characterized in that: For a child node that fails in competition, the master node makes it restart competition from the first level.

7. The non-carrier three-state two-bus communication method according to any one of claims 1 to 6, characterized in that: The power supply state, communication state and idle state correspond to different voltage ranges. When the master node switches the state of the bus, it achieves this by controlling the voltage range of the power supply to which it is connected.

8. The non-carrier three-state two-bus communication method according to claim 7, characterized in that: Each sub-node is provided with a power management module, which is connected to the bus. When the bus is in a power supply state, the power supply of each sub-node is obtained from the bus.

9. The non-carrier three-state two-bus communication method according to claim 7, characterized in that: The master node is provided with a sub-node conflict counting module, which includes a sampling resistor and a voltage sampling circuit, and is used to count the sub-nodes that have applied for interruption when the bus is in a communication state; the sub-node is provided with a constant current circuit, and is used to connect the constant current circuit with the bus when the sub-node applies for interruption, so that a constant current flows through the sampling resistor of the master node to form a unit voltage, and the master node determines whether there is a sub-node applying for interruption and the number of sub-nodes applying based on the voltage drop measured by the voltage sampling circuit.

10. A non-carrier three-state two-bus communication system, comprising a master node and a plurality of sub-nodes, characterized in that: The master node and the sub-node adopt the non-carrier three-state two-bus communication method described in claims 1-9.

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