Bus connection network and impedance matching control method thereof

Abstract

The invention relates to a bus connection network and an impedance matching control method thereof. The bus connection network comprises a plurality of network node devices provided with first and second connection ends; all the network node devices are connected with the network bus through the first connecting end according to a preset sequence and form a cascade relation through the second connecting end according to the preset sequence; the controller is used for controlling all the network node devices to simultaneously generate a first preset signal through the second connecting end and output the first preset signal according to the same direction as the preset sequence and to simultaneously generate a second preset signal through the second connecting end and output the second preset signal according to the direction opposite to the preset sequence; when the network node equipment only receives one of the first preset signal and the second preset signal, the network node equipment is set as endpoint equipment; and controlling the endpoint equipment to switch the matched resistor to access the network bus. By implementing the invention, the matching resistor setting process in the bus connection network can be automatically realized, so that the impedance matching process of the whole bus connection network is more convenient and quicker.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and more specifically, to a bus connection network and an impedance matching control method thereof. Background Art

[0002] The commonly used single battery management system usually includes a battery control unit BCU (Battery Control Unit) and several battery management units BMU (Battery Manage Unit). When the battery management units BCU of multiple battery management systems are connected in sequence through the CAN bus, a parallel energy storage system is formed. In order to ensure the communication quality of the CAN bus, it is usually necessary to connect a 120Ω matching resistor to the CAN-H and CAN-L at both ends of the bus, so that the resistance between CAN-H and CAN-L is maintained at 60Ω. The commonly used method at present is to manually connect the matching resistor to the CAN bus through external wiring, or to build a 120Ω resistor in each battery control unit BCU, and then use the dip switch. Manual operation makes the CAN-H and CAN-L of the battery control unit BCU at the head and tail ends connect a 120Ω matching resistor. Whether it is the solution of the dip switch or the method of connecting the matching resistor separately outside, manual participation is required, which increases the labor cost of installing and debugging the system, and it is easy to miss the matching resistor, which leads to abnormal CAN bus communication and increases the difficulty of system maintenance. In addition, when the number of parallel machines changes, the connection position of the matching resistor needs to be modified synchronously, which increases labor input. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a bus connection network and an impedance matching control method thereof in view of the above-mentioned partial technical defects of the prior art.

[0004] The technical solution adopted by the present invention to solve the technical problem is: constructing a bus connection network, including a plurality of network node devices provided with a first connection terminal, a second connection terminal, a matching resistor, a switch and a controller;

[0005] All the network node devices are connected to the network bus through the first connection end in a preset order, and the network node devices form a cascade relationship through the second connection end in the preset order;

[0006] Wherein, the controller is used to perform the following process when the network node device enters the working state:

[0007] Control all the network node devices to simultaneously generate a first preset signal through the second connection end and output it in the same direction as the preset sequence, and respectively determine whether the network node devices have received the first preset signal;

[0008] Control all the network node devices to simultaneously generate a second preset signal through the second connection end and output it in a direction opposite to the preset sequence, and respectively determine whether the network node devices receive the second preset signal;

[0009] When it is determined that the network node device receives only one of the first preset signal and the second preset signal, setting the network node device as an endpoint device of the bus connection network;

[0010] The switching switches in the endpoint devices are controlled respectively to switch the matching resistors to access the network bus through the switching switches, and keep the matching resistors in other network node devices disconnected from the network bus.

[0011] Preferably, in the bus connection network described in the present invention, the second connection end includes a first port and a second port; the first port of the network node device is connected to the second port of the upper-level network node device, or the second port of the network node device is connected to the first port of the lower-level network node device;

[0012] The controller is also used to perform the following process:

[0013] Control all the network node devices to simultaneously generate the first preset signal through the first port within a first time period, and respectively determine whether the second port of the network node device receives the first preset signal;

[0014] Control all the network node devices to simultaneously generate the second preset signal through the second port within a second time period, and respectively determine whether the first port of the network node device receives the second preset signal; the first time period does not overlap with the second time period.

[0015] Preferably, in the bus connection network described in the present invention, the second connection end includes a third port, a fourth port, a fifth port and a sixth port; the third port and the fourth port of the network node device respectively correspond to the fifth port and the sixth port connected to the upper-level network node device, or the fifth port and the sixth port of the network node device respectively correspond to the third port and the fourth port connected to the lower-level network node device;

[0016] The controller is also used to perform the following process:

[0017] Control all the network node devices to generate the first preset signal through the third port at the same time, and respectively determine whether the fifth port of the network node device receives the first preset signal;

[0018] Control all the network node devices to generate the second preset signal through the sixth port at the same time, and judge whether the fourth port of the network node device receives the second preset signal respectively.

[0019] Preferably, in the bus connection network described in the present invention, the controller controls the network node device to generate the first preset signal and the second preset signal at the same or different time points.

[0020] Preferably, the bus connection network of the present invention further comprises a master node device, the master node device is connected to the network bus and is located at the starting end of the preset sequence, and when the master node device is connected to the network bus, the matching resistor of the master node device is directly connected to the network bus;

[0021] The controller is also used to perform the following process:

[0022] Control all the network node devices to simultaneously generate a second preset signal through the second connection end and output it in a direction opposite to the preset order, and respectively determine whether the network node devices have received the second preset signal; when it is determined that the network node device has not received the second preset signal, set the network node device as an endpoint device of the bus-connected network.

[0023] The present invention also constructs a bus connection network impedance matching control method, wherein the bus connection network includes a plurality of network node devices provided with a first connection terminal, a second connection terminal, a matching resistor, and a switching switch; all the network node devices are connected to the network bus through the first connection terminal in a preset order, and the network node devices form a cascade relationship through the second connection terminal in the preset order;

[0024] The method comprises: when the network node device enters a working state,

[0025] Control all the network node devices to simultaneously generate a first preset signal through the second connection end and output it in the same direction as the preset sequence, and respectively determine whether the network node devices have received the first preset signal;

[0026] Control all the network node devices to simultaneously generate a second preset signal through the second connection end and output it in a direction opposite to the preset sequence, and respectively determine whether the network node devices receive the second preset signal;

[0027] When it is determined that the network node device receives only one of the first preset signal and the second preset signal, setting the network node device as an endpoint device of the bus connection network;

[0028] The switching switches in the endpoint devices are controlled respectively to switch the matching resistors to access the network bus through the switching switches, and keep the matching resistors in other network node devices disconnected from the network bus.

[0029] Preferably, in the bus connection network impedance matching control method of the present invention, the second connection end includes a first port and a second port; the first port of the network node device is connected to the second port of the upper-level network node device, or the second port of the network node device is connected to the first port of the lower-level network node device;

[0030] The method further comprises:

[0031] Control all the network node devices to simultaneously generate the first preset signal through the first port within a first time period, and respectively determine whether the second port of the network node device receives the first preset signal;

[0032] Control all the network node devices to simultaneously generate the second preset signal through the second port within a second time period, and respectively determine whether the first port of the network node device receives the second preset signal; the first time period does not overlap with the second time period.

[0033] Preferably, in the bus connection network impedance matching control method of the present invention, the second connection end includes a third port, a fourth port, a fifth port and a sixth port; the third port and the fourth port of the network node device correspond to the fifth port and the sixth port of the upper network node device, or the fifth port and the sixth port of the network node device correspond to the third port and the fourth port of the lower network node device;

[0034] The method further comprises:

[0035] Control all the network node devices to generate the first preset signal through the third port at the same time, and respectively determine whether the fifth port of the network node device receives the first preset signal;

[0036] Control all the network node devices to generate the second preset signal through the sixth port at the same time, and judge whether the fourth port of the network node device receives the second preset signal respectively.

[0037] Preferably, in the bus connection network impedance matching control method of the present invention, the method further comprises:

[0038] The network node device is controlled to generate the first preset signal and the second preset signal at the same or different time points.

[0039] Preferably, in the bus connection network impedance matching control method of the present invention, the bus connection network further comprises a master node device, the master node device is connected to the network bus and is located at the starting end of the preset sorting, and when the master node device is connected to the network bus, the matching resistor of the master node device is directly connected to the network bus;

[0040] The method further comprises:

[0041] Control all the network node devices to simultaneously generate a second preset signal through the second connection end and output it in a direction opposite to the preset order, and respectively determine whether the network node devices have received the second preset signal; when it is determined that the network node device has not received the second preset signal, set the network node device as an endpoint device of the bus-connected network.

[0042] The implementation of the bus connection network and impedance matching control method thereof of the present invention has the following beneficial effects: the matching resistance setting process in the bus connection network can be automatically realized, making the impedance matching process of the entire bus connection network more convenient and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0044] Figure 1 It is a structural diagram of an embodiment of a bus connection network of the present invention;

[0045] Figure 2 is based on Figure 1 A program flow chart of an impedance matching control method for a bus connection network;

[0046] Figure 3 is a schematic structural diagram of another embodiment of the bus connection network of the present invention;

[0047] Figure 4 is based on Figure 3 A program flow chart of an impedance matching control method for a bus connection network;

[0048] Figure 5 is a schematic structural diagram of another embodiment of the bus connection network of the present invention;

[0049] Figure 6 is based on Figure 5 A program flow chart of an impedance matching control method for a bus connection network;

[0050] Figure 7 is a schematic structural diagram of another embodiment of the bus connection network of the present invention;

[0051] Figure 8 is based on Figure 7 A program flow chart of an impedance matching control method for a bus connection network. DETAILED DESCRIPTION

[0052] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0053] like Figure 1 As shown, an embodiment of the bus connection network of the present invention is disclosed. Figure 1 In the embodiment of the bus connection network of the present invention shown, a plurality of network node devices 100 are provided with a first connection terminal 110, a second connection terminal 120, a matching resistor 130, a switch 140 and a controller (not shown in the figure); all network node devices 100 are connected to the network bus 200 through the first connection terminal 110 in a preset order, and the network node devices 100 form a cascade relationship through the second connection terminal 120 in a preset order. Figure 2 As shown, the controller is used to perform the following processes when the network node device 100 enters the working state: S1, control all network node devices 100 to generate a first preset signal through the second connection terminal 120 at the same time and output it in the same direction as the preset sequence, and judge whether the network node device 100 receives the first preset signal; S2, control all network node devices 100 to generate a second preset signal through the second connection terminal 120 at the same time and output it in the opposite direction of the preset sequence, and judge whether the network node device 100 receives the second preset signal; S3, when it is determined that the network node device 100 only receives one of the first preset signal and the second preset signal, set the network node device 100 as an endpoint device of the bus-connected network; S4, respectively control the switching switches 140 in the endpoint devices to switch the matching resistors 130 to access the network bus 200 through the switching switches 140, and keep the matching resistors 130 in other network node devices 100 disconnected from the network bus 200.

[0054] Specifically, the bus connection network may include several network node devices 100. Each network node device 100 may include a first connection terminal 110 for connecting to a network bus 200, a second connection terminal 120 for connecting to other network node devices 100, and a matching resistor 130 for impedance matching. The switching switch 140 is controlled to control whether the matching resistor 130 of a certain network node device 100 is connected to the network bus 200. For example, when the network node device 100 is connected to the network bus 200, the matching resistor 130 of the network node device 100 is switched to the network bus 200 by controlling the switching switch 140 to achieve impedance matching of the network bus 200 in the entire bus connection network. All network node devices 100 are connected to the network bus 200 according to a preset sequence, that is, according to the preset sequence, the endpoint device at the physical position of the bus connection network can be clearly obtained. All network node devices 100 form a cascade relationship through the second connection terminal 120 according to the preset sequence. Among them, the second connection terminal 120 of the network node device 100 has at least two physical connection interfaces, one for connecting to the upper network node device 100, and the other for connecting to the lower network node device 100. It can be understood that in the cascade relationship, the second connection terminal 120 of the network node device 100 at the head does not need to be connected to the upper network node device 100, and the second connection terminal 120 of the network node device 100 at the tail does not need to be connected to the lower network node device 100. Among them, the first connection terminal 110 can also include multiple connection ports, which are respectively used to connect the two signal lines of the network bus 200. For example, the CAN-H and CAN-L lines of the CAN bus are connected. In addition, different network node devices 100 may include multiple first connection terminals 110, and the network bus 200 can be connected in series between multiple first connection terminals 110.

[0055] In the bus connection network, when a network node device 100 enters the working state, the controller controls all network node devices 100 to generate a first preset signal through the second connection terminal 120 at the same time, and all first preset signals are output to the lower level in the same direction as the preset order. It can be understood that the network node device 100 at the tail, even if there is no lower-level network node device 100, because it cannot judge that it is at the tail, will also generate a first preset signal and output it in the same direction as the preset order. At the same time that the network node device 100 outputs the first preset signal, it is judged whether the network node device 100 receives the first preset signal. That is, when the network node device 100 has an upper-level network node device 100, that is, it is not the first in the preset order, it can receive the first preset signal generated by the upper-level network node device 100. It can be understood that the first preset signal can be in any form, for example, it can be a preset level or waveform.

[0056] Similarly, in the bus connection network, when a network node device 100 enters the working state, the controller controls all network node devices 100 to generate a second preset signal through the second connection terminal 120 at the same time, and all second preset signals are output to the upper level in the opposite direction of the preset sequence. It can be understood that the network node device 100 at the top, even if there is no upper network node device 100, because it cannot judge that it is at the end, it will also generate a second preset signal and output it in the opposite direction of the preset sequence. While the network node device 100 outputs the second preset signal, it is judged whether the network node device 100 receives the second preset signal. That is, when the network node device 100 has a lower network node device 100, that is, it is not at the end of the preset sequence, it can receive the second preset signal generated by the lower network node device 100. It can be understood that the second preset signal can be in any form, for example, it can be a preset level or waveform.

[0057] Based on the above process, it can be known that the network node device 100 located in the middle position of the preset sequence will receive the first preset signal generated by the upper-level network node device 100 and the second preset signal generated by the lower-level network node device 100. When it can be determined that a certain network node device 100 can only receive one of the first preset signal and the second preset signal, it is possible to determine the head and tail of the network node device 100 in the preset sequence. In addition, by enabling the network node device 100 to receive at least one of the first preset signal or the second preset signal, it is further ensured that the network node device 100 is in a state of accessing the bus connection network. Through the above process, the automatic setting of the matching impedance in the bus connection network can be achieved. In particular, when the state of the network node device 100, such as the number, changes, adjustments can be made quickly to re-complete the impedance matching of the entire bus connection network.

[0058] In one embodiment, if Figure 3 As shown, the second connection end 120 includes a first port 121 and a second port 122; the first port 121 of the network node device 100 is connected to the second port 122 of the upper network node device 100, or the second port 122 of the network node device 100 is connected to the first port 121 of the lower network node device 100. Figure 4As shown, the controller is also used to perform the following process: S1A, control all network node devices 100 to generate a first preset signal through the first port 121 in the first time period at the same time, and respectively determine whether the second port 122 of the network node device 100 receives the first preset signal; S2A, control all network node devices 100 to generate a second preset signal through the second port 122 in the second time period at the same time, and respectively determine whether the first port 121 of the network node device 100 receives the second preset signal; the first time period does not overlap with the second time period. Specifically, in each network node device 100, the second connection end 120 includes a first port 121 and a second port 122, and the network node device 100 is connected to the lower-level network node device 100 through the first port 121, or to the upper-level network node device 100 through the second port 122, and finally forms a cascade relationship.

[0059] In this cascade relationship, when a network node device 100 enters the working state, the controller controls all network node devices 100 to simultaneously generate a first preset signal through the first port 121 within the first time period. Because the first port 121 of the network node device 100 is cascaded to the lower level in the same direction as the preset order, similarly, the first preset signals generated by all first ports 121 will be output in the same direction as the preset order. While the first port 121 of the network node device 100 outputs the first preset signal, it is judged whether the second port 122 of the network node device 100 receives the first preset signal. That is, when the network node device 100 has an upper-level network node device 100, that is, it is not the first in the preset order, it can receive the first preset signal generated by the upper-level network node device 100.

[0060] In this cascade relationship, when a network node device 100 enters the working state, the controller controls all network node devices 100 to simultaneously generate a second preset signal through the second port 122 within the second time period. Because the second port 122 of the network node device 100 is cascaded to the upper level in the opposite direction of the preset sequence, the second preset signal generated by the second port 122 will also be output in the opposite direction of the preset sequence. While the second port 122 of the network node device 100 outputs the second preset signal, it is judged whether the first port 121 of the network node device 100 receives the second preset signal. That is, when the network node device 100 has an upper-level network node device 100, that is, it is not at the end of the preset sequence, it can receive the second preset signal generated by the lower-level network node device 100.

[0061] It should be emphasized here that the generation time of the first preset signal and the second preset signal is staggered, that is, the first preset time period and the second preset time period cannot overlap, but it is not limited to generating the first preset signal first or generating the second preset signal first. Based on the process of step S3 and step S4, it can be known that the network node device 100 located in the middle position of the preset sequence will receive the first preset signal generated by the upper network node device 100 and the second preset signal generated by the lower network node device 100. When it can be determined that a certain network node device 100 can only receive one of the first preset signal and the second preset signal, it can be determined that the network node device 100 is the head and tail of the preset sequence. In addition, the network node device 100 can receive at least one of the first preset signal or the second preset signal, which further ensures that the network node device 100 is in the state of accessing the bus connection network. Through the above process, the automatic setting of the matching impedance in the bus connection network can be realized. In particular, when the state of the network node device 100, such as the number, changes, it can be quickly adjusted to re-complete the impedance matching of the entire bus connection network.

[0062] In one embodiment, if Figure 5 As shown, the second connection end 120 includes a third port 123, a fourth port 124, a fifth port 125 and a sixth port 126; the third port 123 and the fourth port 124 of the network node device 100 are respectively connected to the fifth port 125 and the sixth port 126 of the upper network node device 100, or the fifth port 125 and the sixth port 126 of the network node device 100 are respectively connected to the third port 123 and the fourth port 124 of the lower network node device 100. Figure 6 As shown, the controller is also used to perform the following process: S1B, control all network node devices 100 to generate a first preset signal through the third port 123 at the same time, and respectively determine whether the fifth port 125 of the network node device 100 receives the first preset signal; S2B, control all network node devices 100 to generate a second preset signal through the sixth port 126 at the same time, and respectively determine whether the fourth port 124 of the network node device 100 receives the second preset signal. Specifically, in each network node device 100, the second connection end 120 includes the third port 123, the fourth port 124, the fifth port 125 and the sixth port 126, and the network node device 100 is connected to the lower-level network node device 100 through the third port 123 and the fourth port 124, or to the upper-level network node device 100 through the fifth port 125 and the sixth port 126, and finally forms a cascade relationship.

[0063] In this cascade relationship, when a network node device 100 enters the working state, the controller controls all network node devices 100 to simultaneously generate the first preset signal through the third port 123. Because the third port 123 of the network node device 100 is cascaded to the lower level in the same direction as the preset order, similarly, the first preset signals generated by all third ports 123 will be output in the same direction as the preset order. While the third port 123 of the network node device 100 outputs the first preset signal, it is judged whether the fifth port 125 of the network node device 100 receives the first preset signal. That is, when the network node device 100 has an upper-level network node device 100, that is, it is not the first in the preset order, it can receive the first preset signal generated by the upper-level network node device 100.

[0064] In this cascade relationship, when a network node device 100 enters the working state, the controller controls all network node devices 100 to simultaneously generate a second preset signal through the sixth port 126. Because the sixth port 126 of the network node device 100 is cascaded to the upper level in the opposite direction of the preset sequence, the second preset signal generated by the sixth port 126 will also be output in the opposite direction of the preset sequence. While the sixth port 126 of the network node device 100 outputs the second preset signal, it is judged whether the fourth port 124 of the network node device 100 receives the second preset signal. That is, when the network node device 100 has an upper-level network node device 100, that is, it is not at the end of the preset sequence, it can receive the second preset signal generated by the lower-level network node device 100.

[0065] Based on the process of step S3 and step S4, it can be known that the network node device 100 located in the middle position of the preset sequence will receive the first preset signal generated by the upper-level network node device 100 and the second preset signal generated by the lower-level network node device 100. When it can be determined that a certain network node device 100 can only receive one of the first preset signal and the second preset signal, it is possible to determine the head and tail of the network node device 100 in the preset sequence. In addition, by the network node device 100 being able to receive at least one of the first preset signal or the second preset signal, it is further ensured that the network node device 100 is in a state of being connected to the bus connection network. Through the above process, the automatic setting of the matching impedance in the bus connection network can be achieved. In particular, when the state of the network node device 100, such as the number, changes, adjustments can be made quickly to re-complete the impedance matching of the entire bus connection network.

[0066] Among them, in this cascade relationship, since the network node device 100 generates the first preset signal and the second preset signal through different ports, the network node device 100 can generate the first preset signal and the second preset signal at the same time, or generate the first preset signal and the second preset signal in time-sharing.

[0067] In one embodiment, if Figure 7 As shown, the bus connection network of the present invention also includes a master node device 300, which is connected to the network bus 200 and is located at the starting end of the preset sequence, and when the master node device 300 is connected to the network bus 200, the matching resistor 130 of the master node device 300 is directly connected to the network bus 200. Figure 8 As shown, the controller is also used to perform the following process: S2C, control all network node devices 100 to generate a second preset signal through the second connection terminal 120 at the same time and output it in the opposite direction of the preset sequence, and respectively determine whether the network node device 100 receives the second preset signal; S3C, when it is determined that the network node device 100 does not receive the second preset signal, set the network node device 100 as the endpoint device of the bus connection network. Specifically, when it has been clarified that one end of the network bus 200 has been provided with a matching resistor 130, the matching resistor 130 of the endpoint is connected through the master node device 300 set at the starting end of the preset sequence. It is only necessary to determine the endpoint device at the other end of the bus connection network and connect the matching resistor 130. In this judgment process, with the master node device 300 as the starting end of the preset sequence, all network node devices 100 are controlled to generate a second preset signal through the second connection terminal 120 at the same time, and all second preset signals are output to the upper level in sequence in the opposite direction of the preset sequence. While the network node device 100 outputs the second preset signal, it is determined whether the network node device 100 has received the second preset signal. That is, when the network node device 100 has a lower-level network node device 100, which is not the tail of the preset sequence, it can receive the second preset signal generated by the lower-level network node device 100. Once it is determined that the network node device 100 has not received the second preset signal, it can be determined that the network node device 100 is the last one in the preset sequence, that is, another endpoint device of the entire bus connection network is obtained. Based on the above step S4, the switching switch 140 in the endpoint device is set so that the matching resistor 130 in the endpoint device is connected to the network bus 200.

[0068] In addition, in the bus connection network impedance matching control method of the present invention, if Figure 1As shown, the bus connection network includes a plurality of network node devices 100 provided with a first connection terminal 110, a second connection terminal 120, a matching resistor 130, and a switch 140; all network node devices 100 are connected to the network bus 200 through the first connection terminal 110 in a preset order, and the network node devices 100 form a cascade relationship through the second connection terminal 120 in a preset order. Figure 2 As shown, in the bus-connected network impedance matching control method of the present invention, it specifically includes: when the network node device 100 enters the working state, S1, control all network node devices 100 to generate a first preset signal through the second connection terminal 120 at the same time and output it in the same direction as the preset sequence, and respectively judge whether the network node device 100 receives the first preset signal; S2, control all network node devices 100 to generate a second preset signal through the second connection terminal 120 at the same time and output it in the opposite direction of the preset sequence, and respectively judge whether the network node device 100 receives the second preset signal; S3, when it is determined that the network node device 100 only receives one of the first preset signal and the second preset signal, set the network node device 100 as the endpoint device of the bus-connected network; S4, respectively control the switching switch 140 in the endpoint device to switch the matching resistor 130 to access the network bus 200 through the switching switch 140, and keep the matching resistor 130 in other network node devices 100 disconnected from the network bus 200.

[0069] Specifically, the bus connection network may include several network node devices 100. Each network node device 100 may include a first connection terminal 110 for connecting to a network bus 200, a second connection terminal 120 for connecting to other network node devices 100, and a matching resistor 130 for impedance matching. The switching switch 140 is controlled to control whether the matching resistor 130 of a certain network node device 100 is connected to the network bus 200. For example, when the network node device 100 is connected to the network bus 200, the matching resistor 130 of the network node device 100 is switched to the network bus 200 by controlling the switching switch 140 to achieve impedance matching of the network bus 200 in the entire bus connection network. All network node devices 100 are connected to the network bus 200 according to a preset sequence, that is, according to the preset sequence, the endpoint device at the physical position of the bus connection network can be clearly obtained. All network node devices 100 form a cascade relationship through the second connection terminal 120 according to the preset sequence. It can be understood that the second connection terminal 120 of the network node device 100 has at least two physical connection interfaces, one for connecting to the upper network node device 100, and one for connecting to the lower network node device 100. It can be understood that in the cascade relationship, the second connection terminal 120 of the network node device 100 at the head does not need to be connected to the upper network node device 100, and the second connection terminal 120 of the network node device 100 at the tail does not need to be connected to the lower network node device 100. Among them, the first connection terminal 110 can also include two connection ports, which are respectively used to connect the two signal lines of the bus. For example, the CAN-H and CAN-L lines of the CAN bus are connected. In addition, different network node devices 100 can include multiple first connection terminals 110, and the network bus 200 can be connected in series between multiple first connection terminals 110.

[0070] In the bus connection network, when a network node device 100 enters the working state, all network node devices 100 are controlled to generate a first preset signal through the second connection terminal 120 at the same time, and all first preset signals are output to the lower level in the same direction as the preset order. It can be understood that the network node device 100 located at the tail, even if there is no lower-level network node device 100, because it cannot judge that it is at the tail, it will also generate a first preset signal and output it in the same direction as the preset order. At the same time that the network node device 100 outputs the first preset signal, it is judged whether the network node device 100 receives the first preset signal. That is, when the network node device 100 has an upper-level network node device 100, that is, it is not the first in the preset order, it can receive the first preset signal generated by the upper-level network node device 100. It can be understood that the first preset signal can be in any form, for example, it can be a preset level or waveform.

[0071] Similarly, in the bus connection network, when a network node device 100 enters the working state, all network node devices 100 are controlled to generate a second preset signal through the second connection terminal 120 at the same time, and all second preset signals are output to the upper level in sequence in the opposite direction of the preset sequence. It can be understood that the network node device 100 at the top, even if there is no upper network node device 100, because it cannot determine that it is at the end, it will also generate a second preset signal and output it in the opposite direction of the preset sequence. While the network node device 100 outputs the second preset signal, it is judged whether the network node device 100 receives the second preset signal. That is, when the network node device 100 has a lower network node device 100, that is, it is not at the end of the preset sequence, it can receive the second preset signal generated by the lower network node device 100. It can be understood that the second preset signal can be in any form, for example, it can be a preset level or waveform.

[0072] Based on the above process, it can be known that the network node device 100 located in the middle position of the preset sequence will receive the first preset signal generated by the upper-level network node device 100 and the second preset signal generated by the lower-level network node device 100. When it can be determined that a certain network node device 100 can only receive one of the first preset signal and the second preset signal, it is possible to determine the head and tail of the network node device 100 in the preset sequence. In addition, by enabling the network node device 100 to receive at least one of the first preset signal or the second preset signal, it is further ensured that the network node device 100 is in a state of accessing the bus connection network. Through the above process, the automatic setting of the matching impedance in the bus connection network can be achieved. In particular, when the state of the network node device 100, such as the number, changes, adjustments can be made quickly to re-complete the impedance matching of the entire bus connection network.

[0073] In one embodiment, if Figure 3 As shown, in the network node device 100, the second connection end 120 includes a first port 121 and a second port 122; the first port 121 of the network node device 100 is connected to the second port 122 of the upper network node device 100, or the second port 122 of the network node device 100 is connected to the first port 121 of the lower network node device 100. Figure 4As shown, the corresponding bus connection network impedance matching control method also includes: S1A, controlling all network node devices 100 to simultaneously generate a first preset signal through the first port 121 within a first time period, and respectively judging whether the second port 122 of the network node device 100 receives the first preset signal; S2A, controlling all network node devices 100 to simultaneously generate a second preset signal through the second port 122 within a second time period, and respectively judging whether the first port 121 of the network node device 100 receives the second preset signal; the first time period does not overlap with the second time period. Specifically, in each network node device 100, the second connection end 120 includes a first port 121 and a second port 122, and the network node device 100 is connected to the lower-level network node device 100 through the first port 121, or to the upper-level network node device 100 through the second port 122, and finally forms a cascade relationship.

[0074] In this cascade relationship, when a network node device 100 enters the working state, all network node devices 100 are controlled to generate the first preset signal through the first port 121 simultaneously within the first time period. Because the first port 121 of the network node device 100 is cascaded to the lower level in the same direction as the preset order, similarly, the first preset signals generated by all first ports 121 will be output in the same direction as the preset order. While the first port 121 of the network node device 100 outputs the first preset signal, it is judged whether the second port 122 of the network node device 100 receives the first preset signal. That is, when the network node device 100 has an upper-level network node device 100, that is, it is not the first in the preset order, it can receive the first preset signal generated by the upper-level network node device 100.

[0075] In this cascade relationship, when a network node device 100 enters the working state, all network node devices 100 are controlled to generate a second preset signal through the second port 122 at the same time in the second time period. Because the second port 122 of the network node device 100 is cascaded to the upper level in the opposite direction of the preset sequence, the second preset signal generated by the second port 122 will also be output in the opposite direction of the preset sequence. While the second port 122 of the network node device 100 outputs the second preset signal, it is judged whether the first port 121 of the network node device 100 receives the second preset signal. That is, when the network node device 100 has an upper-level network node device 100, that is, it is not at the end of the preset sequence, it can receive the second preset signal generated by the lower-level network node device 100.

[0076] It should be emphasized here that the generation time of the first preset signal and the second preset signal is staggered, that is, the first preset time period and the second preset time period cannot overlap, but it is not limited to generating the first preset signal first or generating the second preset signal first. Based on the process of step S3 and step S4, it can be known that the network node device 100 located in the middle position of the preset sequence will receive the first preset signal generated by the upper network node device 100 and the second preset signal generated by the lower network node device 100. When it can be determined that a certain network node device 100 can only receive one of the first preset signal and the second preset signal, it can be determined that the network node device 100 is the head and tail of the preset sequence. In addition, the network node device 100 can receive at least one of the first preset signal or the second preset signal, which further ensures that the network node device 100 is in the state of accessing the bus connection network. Through the above process, the automatic setting of the matching impedance in the bus connection network can be realized. In particular, when the state of the network node device 100, such as the number, changes, it can be quickly adjusted to re-complete the impedance matching of the entire bus connection network.

[0077] In one embodiment, if Figure 5 As shown, the second connection end 120 includes a third port 123, a fourth port 124, a fifth port 125 and a sixth port 126; the third port 123 and the fourth port 124 of the network node device 100 are respectively connected to the fifth port 125 and the sixth port 126 of the upper network node device 100, or the fifth port 125 and the sixth port 126 of the network node device 100 are respectively connected to the third port 123 and the fourth port 124 of the lower network node device 100. Figure 6 As shown, the corresponding bus connection network impedance matching control method also includes: S1B, controlling all network node devices 100 to generate a first preset signal through the third port 123 at the same time, and respectively judging whether the fifth port 125 of the network node device 100 receives the first preset signal; S2B, controlling all network node devices 100 to generate a second preset signal through the sixth port 126 at the same time, and respectively judging whether the fourth port 124 of the network node device 100 receives the second preset signal. Specifically, in each network node device 100, the second connection end 120 includes a third port 123, a fourth port 124, a fifth port 125 and a sixth port 126, and the network node device 100 is connected to the lower-level network node device 100 through the third port 123 and the fourth port 124, or to the upper-level network node device 100 through the fifth port 125 and the sixth port 126, and finally forms a cascade relationship.

[0078] In this cascade relationship, when a network node device 100 enters the working state, all network node devices 100 are controlled to generate the first preset signal through the third port 123 at the same time. Because the third port 123 of the network node device 100 is cascaded to the lower level in the same direction as the preset order, similarly, the first preset signals generated by all third ports 123 will be output in the same direction as the preset order. While the third port 123 of the network node device 100 outputs the first preset signal, it is judged whether the fifth port 125 of the network node device 100 receives the first preset signal. That is, when the network node device 100 has an upper-level network node device 100, that is, it is not the first in the preset order, it can receive the first preset signal generated by the upper-level network node device 100.

[0079] In this cascade relationship, when a network node device 100 enters the working state, all network node devices 100 are controlled to generate a second preset signal through the sixth port 126 at the same time. Because the sixth port 126 of the network node device 100 is cascaded to the upper level in the opposite direction of the preset sequence, the second preset signal generated by the sixth port 126 will also be output in the opposite direction of the preset sequence. While the sixth port 126 of the network node device 100 outputs the second preset signal, it is judged whether the fourth port 124 of the network node device 100 receives the second preset signal. That is, when the network node device 100 has an upper-level network node device 100, that is, it is not the tail of the preset sequence, it can receive the second preset signal generated by the lower-level network node device 100.

[0080] Based on the process of step S3 and step S4, it can be known that the network node device 100 located in the middle position of the preset sequence will receive the first preset signal generated by the upper-level network node device 100 and the second preset signal generated by the lower-level network node device 100. When it can be determined that a certain network node device 100 can only receive one of the first preset signal and the second preset signal, it is possible to determine the head and tail of the network node device 100 in the preset sequence. In addition, by the network node device 100 being able to receive at least one of the first preset signal or the second preset signal, it is further ensured that the network node device 100 is in a state of being connected to the bus connection network. Through the above process, the automatic setting of the matching impedance in the bus connection network can be achieved. In particular, when the state of the network node device 100, such as the number, changes, adjustments can be made quickly to re-complete the impedance matching of the entire bus connection network.

[0081] Among them, in this cascade relationship, since the network node device 100 generates the first preset signal and the second preset signal through different ports, the network node device 100 can generate the first preset signal and the second preset signal at the same time, or generate the first preset signal and the second preset signal in time-sharing.

[0082] In one embodiment, if Figure 7 As shown, the bus connection network also includes a master node device 300, which is connected to the network bus 200 and is located at the starting end of the preset sequence, and when the master node device 300 is connected to the network bus 200, the matching resistor 130 of the master node device 300 is directly connected to the network bus 200. Figure 8 As shown, the corresponding S2C controls all network node devices 100 to generate the second preset signal through the second connection terminal 120 at the same time and outputs it in the opposite direction of the preset sequence, and judges whether the network node device 100 receives the second preset signal; S3C, when it is determined that the network node device 100 does not receive the second preset signal, the network node device 100 is set as the endpoint device of the bus connection network. Specifically, when it has been clarified that one end of the network bus 200 has been provided with a matching resistor 130, the matching resistor 130 of the endpoint is connected through the master node device 300 set at the starting end of the preset sequence. It is only necessary to determine the endpoint device at the other end of the bus connection network and connect the matching resistor 130. In the judgment process, the master node device 300 is used as the starting end of the preset sequence, and all network node devices 100 are controlled to generate the second preset signal through the second connection terminal 120 at the same time, and all the second preset signals are output to the upper level in sequence in the opposite direction of the preset sequence. While the network node device 100 outputs the second preset signal, it is judged whether the network node device 100 receives the second preset signal. That is, when the network node device 100 has a lower-level network node device 100, that is, it is not the tail of the preset sequence, it can receive the second preset signal generated by the lower-level network node device 100. Once it is determined that the network node device 100 has not received the second preset signal, it can be determined that the network node device 100 is the last one of the preset sequence, that is, another endpoint device of the entire bus connection network is obtained. Based on the above step S4, the switching switch 140 in the endpoint device is set so that the matching resistor 130 in the endpoint device is connected to the network bus 200.

[0083] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A bus connection network, characterized in that: It includes a plurality of network node devices provided with a first connection terminal, a second connection terminal, a matching resistor, a switching switch and a controller; All the network node devices are connected to the network bus through the first connection end in a preset order, and the network node devices form a cascade relationship through the second connection end in the preset order; Wherein, the controller is used to perform the following process when the network node device enters the working state: Control all the network node devices to simultaneously generate a first preset signal through the second connection end and output it in the same direction as the preset sequence, and respectively determine whether the network node devices have received the first preset signal; Control all the network node devices to simultaneously generate a second preset signal through the second connection end and output it in a direction opposite to the preset sequence, and respectively determine whether the network node devices receive the second preset signal; When it is determined that the network node device receives only one of the first preset signal and the second preset signal, setting the network node device as an endpoint device of the bus connection network; The switching switches in the endpoint devices are controlled respectively to switch the matching resistors to access the network bus through the switching switches, and keep the matching resistors in other network node devices disconnected from the network bus.

2. The bus connection network according to claim 1, characterized in that: The second connection end includes a first port and a second port; the first port of the network node device is connected to the second port of the upper-level network node device, or the second port of the network node device is connected to the first port of the lower-level network node device; The controller is also used to perform the following process: Control all the network node devices to simultaneously generate the first preset signal through the first port within a first time period, and respectively determine whether the second port of the network node device receives the first preset signal; Control all the network node devices to simultaneously generate the second preset signal through the second port within a second time period, and respectively determine whether the first port of the network node device receives the second preset signal; the first time period does not overlap with the second time period.

3. The bus connection network according to claim 1, characterized in that: The second connection end includes a third port, a fourth port, a fifth port and a sixth port; the third port and the fourth port of the network node device correspond to the fifth port and the sixth port of the upper-level network node device, or the fifth port and the sixth port of the network node device correspond to the third port and the fourth port of the lower-level network node device; The controller is also used to perform the following process: Control all the network node devices to generate the first preset signal through the third port at the same time, and respectively determine whether the fifth port of the network node device receives the first preset signal; Control all the network node devices to generate the second preset signal through the sixth port at the same time, and judge whether the fourth port of the network node device receives the second preset signal respectively.

4. The bus connection network according to claim 3, characterized in that: The controller controls the network node device to generate the first preset signal and the second preset signal at the same or different time points.

5. The bus connection network according to claim 1, characterized in that: It also includes a master node device, which is connected to the network bus and located at the starting end of the preset sequence, and when the master node device is connected to the network bus, the matching resistor of the master node device is directly connected to the network bus; The controller is also used to perform the following process: Control all the network node devices to simultaneously generate a second preset signal through the second connection end and output it in a direction opposite to the preset sequence, and respectively determine whether the network node devices receive the second preset signal; When it is determined that the network node device has not received the second preset signal, the network node device is set as an endpoint device of the bus-connected network.

6. A bus connection network impedance matching control method, characterized in that: The bus connection network includes a plurality of network node devices provided with a first connection terminal, a second connection terminal, a matching resistor, and a switching switch; all the network node devices are connected to the network bus through the first connection terminal in a preset order, and the network node devices form a cascade relationship through the second connection terminal in the preset order; The method comprises: when the network node device enters a working state, Control all the network node devices to simultaneously generate a first preset signal through the second connection end and output it in the same direction as the preset sequence, and respectively determine whether the network node devices have received the first preset signal; Control all the network node devices to simultaneously generate a second preset signal through the second connection end and output it in a direction opposite to the preset sequence, and respectively determine whether the network node devices receive the second preset signal; When it is determined that the network node device receives only one of the first preset signal and the second preset signal, setting the network node device as an endpoint device of the bus connection network; The switching switches in the endpoint devices are controlled respectively to switch the matching resistors to access the network bus through the switching switches, and keep the matching resistors in other network node devices disconnected from the network bus.

7. The bus connection network impedance matching control method according to claim 6, characterized in that: The second connection end includes a first port and a second port; the first port of the network node device is connected to the second port of the upper-level network node device, or the second port of the network node device is connected to the first port of the lower-level network node device; The method further comprises: Control all the network node devices to simultaneously generate the first preset signal through the first port within a first time period, and respectively determine whether the second port of the network node device receives the first preset signal; Control all the network node devices to simultaneously generate the second preset signal through the second port within a second time period, and respectively determine whether the first port of the network node device receives the second preset signal; the first time period does not overlap with the second time period.

8. The bus connection network impedance matching control method according to claim 6, characterized in that: The second connection end includes a third port, a fourth port, a fifth port and a sixth port; the third port and the fourth port of the network node device correspond to the fifth port and the sixth port of the upper-level network node device, or the fifth port and the sixth port of the network node device correspond to the third port and the fourth port of the lower-level network node device; The method further comprises: Control all the network node devices to generate the first preset signal through the third port at the same time, and respectively determine whether the fifth port of the network node device receives the first preset signal; Control all the network node devices to generate the second preset signal through the sixth port at the same time, and judge whether the fourth port of the network node device receives the second preset signal respectively.

9. The bus connection network impedance matching control method according to claim 8, characterized in that: The method further comprises: The network node device is controlled to generate the first preset signal and the second preset signal at the same or different time points.

10. The bus connection network impedance matching control method according to claim 7, characterized in that: The bus connection network also includes a master node device, which is connected to the network bus and located at the starting end of the preset sequence, and when the master node device is connected to the network bus, the matching resistor of the master node device is directly connected to the network bus; The method further comprises: Control all the network node devices to simultaneously generate a second preset signal through the second connection end and output it in a direction opposite to the preset sequence, and respectively determine whether the network node devices receive the second preset signal; When it is determined that the network node device has not received the second preset signal, the network node device is set as an endpoint device of the bus-connected network.

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