A channel switching circuit and electronic device

Abstract

The application provides a channel switching circuit and an electronic device. The first signal transmission channel of the channel switching circuit is provided with a first control unit. The first control unit is used for selecting one of at least two first input channels as a target input channel, and transmitting the first signal of the target input channel to a second communication device. The holding relay has a first output channel and at least two second input channels. The second input channels are connected to the first input channels in correspondence. The first control unit is used for keeping the second input channel connected to the target input channel connected to the first output channel. In the case of power supply abnormality of the first control unit, the first output channel outputs the first signal of the target input channel to the second communication device. In the application, when the first control unit cannot receive and output the first signal due to power supply abnormality, the holding relay can transmit the first signal of the target input channel to the second communication device, which is beneficial to improving the reliability of the channel switching circuit.

Description

Technical Field

[0001] This application belongs to the field of communication technology, and in particular relates to a channel switching circuit and electronic device. Background Technology

[0002] In the communication switching equipment of power system protection devices, the communication channel switching circuit is a key component. It enables the switching and management between different channels and typically includes control units such as FPGAs. The control unit judges the signal conditions, drives relevant components to operate, and ensures that data is transmitted through the appropriate channel. It is widely used in scenarios such as communication between protection devices in power systems.

[0003] In related technologies, the control unit relies on an external power supply. Once a power supply failure causes the device to lose power, the control unit, such as the FPGA, will stop working and will be unable to output signals to maintain the connection status of the channel, causing the communication channel to be interrupted, affecting the normal communication of the device, and reducing the reliability of the product. Summary of the Invention

[0004] The purpose of this application is to provide a channel switching circuit and electronic device, which aims to solve the problem of low reliability of channel switching circuits in the conventional technology.

[0005] A first aspect of this application provides a channel switching circuit disposed between a first communication device and a second communication device, the channel switching circuit comprising:

[0006] A first signal transmission channel is provided with a first control unit. The first signal transmission channel has at least two first input channels. The at least two first input channels are used to access the first signal of the first communication device. The first control unit is used to select one of the at least two first input channels as a target input channel based on the first signal, and is used to transmit the first signal of the target input channel to the second communication device.

[0007] A holding relay has a first output channel and at least two second input channels, the second input channels being connected to the first input channel and used to acquire the first signal; the first control unit is used to keep the second input channel connected to the target input channel connected to the first output channel.

[0008] In the event of a power supply failure in the first control unit, the first output channel outputs the first signal of the target input channel to the second communication device.

[0009] In some embodiments of this application, the first control unit selects the one with better first signal quality from at least two first input channels as the target input channel.

[0010] In some embodiments of this application, the channel switching circuit includes a first relay, the output terminal of which is used to connect to the second communication device; the first relay has a first reset state and a first set state, in the first reset state, the first relay is connected to the second output channel of the holding relay, and in the first set state, the first relay is connected to the first signal of the first control unit;

[0011] When the first control unit is powered normally, the first relay switches to the first set state; when the first control unit is powered abnormally, the first relay switches to the first reset state.

[0012] In some embodiments of this application, the first control unit is used to switch the first relay from the first reset state to the first set state.

[0013] In some embodiments of this application, the channel switching circuit further includes a second signal transmission channel, which is used to access a second signal from the second communication device;

[0014] The second signal transmission channel has at least two second output channels, each of which is used to output a second signal from the second communication device to the first communication device, and the first communication device outputs the first signal based on the second signal.

[0015] In some embodiments of this application, a second control unit is provided on the second signal transmission channel, and the second control unit is used to select one of the at least two second output channels to output the second signal.

[0016] In some embodiments of this application, the channel switching circuit further includes at least two second relays. The second relays have a second reset state and a second set state. In the second reset state, the second relays receive the second signal of the second communication device and output the second signal to the first communication device. In the second set state, the second relays receive the second signal of the corresponding second output channel and output the second signal to the first communication device.

[0017] In some embodiments of this application, the channel switching circuit further includes a third relay, which is used to receive a second signal from the second communication device and to transmit the second signal to the second control unit when the second control unit is powered normally, and to transmit the second signal to the second relay when the second control unit is powered abnormally.

[0018] In some embodiments of this application, the first control unit and the second control unit are reused.

[0019] A second aspect of this application also provides an electronic device including at least one channel switching circuit as described above, wherein, if there are at least two channel switching circuits, the at least two channel switching circuits are connected in series.

[0020] In some embodiments of this application, the electronic device further includes a first communication device, which is used to receive a second signal output by the channel switching circuit and output a first signal to the first communication device based on the second signal.

[0021] In some embodiments of this application, the electronic device further includes a second communication device, which is used to output a second signal to the channel switching circuit and to receive a first signal output by the channel switching circuit.

[0022] The beneficial effects of this application are as follows: In the channel switching circuit and electronic device of this application, the channel switching circuit is disposed between the first communication device and the second communication device. The channel switching circuit includes a first signal transmission channel and a holding relay. A first control unit is disposed on the first signal transmission channel. The first signal transmission channel has at least two first input channels, and both of the at least two first input channels are used to access the first signal of the first communication device. The first control unit is used to select one of the at least two first input channels as the target input channel based on the first signal, and is used to transmit the first signal of the target input channel to the second communication device. The holding relay has a first output channel and at least two second input channels, the second input channels are correspondingly connected to the first input channels, and are used to acquire the first signal. The control unit is used to keep the second input channel connected to the target input channel connected to the first output channel; in the event of a power failure in the first control unit, the first output channel outputs the first signal of the target input channel to the second communication device; in this application, the first control unit transmits the first signal of the first communication device to the second communication device, and can also transmit the first signal of the target input channel to the second communication device. In addition, when the first control unit is powered abnormally and cannot receive or output the first signal, the relay can still transmit the first signal of the target input channel to the second communication device, which helps to ensure that the first signal is continuously transmitted to the second communication device, thereby helping to avoid communication interruption caused by power failure, and thus improving the communication reliability of the device in scenarios such as power systems. Attached Figure Description

[0023] Figure 1 A schematic diagram of the framework structure of a channel switching circuit provided in an embodiment of this application;

[0024] Figure 2 A schematic diagram of the framework structure of a channel switching circuit provided in another embodiment of this application;

[0025] Figure 3 This is a schematic diagram of the circuit structure of a channel switching circuit provided in an embodiment of this application.

[0026] Specific element symbol explanations: 100-First communication device, 200-Second communication device, 300-First signal transmission channel, 310-First control unit, 320-First input channel, 400-Holding relay, 410-Second input channel, 420-First output channel, 500-First relay, 600-Second signal transmission channel. Detailed Implementation

[0027] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0028] It should be noted that when a component is referred to as being "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0030] It's important to understand that in fields with extremely high reliability requirements, such as power system protection devices, communication channel switching circuits are core components for enabling flexible switching and management of data transmission paths between different sites and devices. They typically include a control module based on FPGAs or similar technologies. This control module can determine and implement the selection, switching, and data processing and transmission of communication channels in real time based on signal quality and transmission requirements. It is widely used in critical scenarios such as information exchange between power system protection devices and remote monitoring signal transmission, and is a vital support for ensuring the stable operation of the power system.

[0031] However, the normal operation of existing communication channel switching circuits is highly dependent on external power supply. When a short-term power outage or power failure causes the device to lose power, the control module, represented by the FPGA, as an active device, will stop working due to the power failure and will be unable to continue outputting control signals to maintain the current channel switching state. This will lead to communication channel interruption, changes in the connection status of the transmitting and receiving ports, and consequently, communication interruption between different sites. This seriously affects the collaborative operation of critical equipment such as power system protection devices and reduces the reliability of the product under extreme power supply conditions.

[0032] Based on this, this application improves the channel switching circuit and electronic equipment in the related technology.

[0033] Please see Figure 1 , Figure 1 This diagram illustrates the framework structure of the channel switching circuit provided in this embodiment. The channel switching circuit is positioned between the first communication device 100 and the second communication device 200. The channel switching circuit includes a first signal transmission channel 300 and a holding relay 400. A first control unit 310 is provided on the first signal transmission channel 300. The first signal transmission channel 300 has at least two first input channels 320, both of which are used to access the first signal from the first communication device. The first control unit 310 is used to select at least two first input channels 320 based on the first signal. One of them is the target input channel, which is used to transmit the first signal of the target input channel to the second communication device 200; the holding relay 400 has a first output channel 420 and at least two second input channels 410, which are connected to the first input channel 320 respectively and are used to acquire the first signal; the first control unit 310 is used to keep the second input channel 410 connected to the target input channel connected to the first output channel 420; in the event of a power failure of the first control unit 310, the first output channel 420 outputs the first signal of the target input channel to the second communication device 200.

[0034] It should be explained that the channel switching circuit is located between the first communication device 100 and the second communication device 200, and is used to switch the signal transmission channel and transmit signals between the two devices. The target input channel is the first input channel 320 selected by the first control unit 310 for transmitting the first signal. The holding relay 400 is a switching element in the channel switching circuit, used to maintain the current state after power failure.

[0035] It is understood that the first signal transmission channel 300 in this embodiment is provided with a first control unit 310 and at least two first input channels 320. The first control unit 310 can flexibly select the target input channel based on the first signal to realize signal transmission control during normal power supply. The second input channel 410 of the holding relay 400 is correspondingly connected to the first input channel 320, and the first control unit 310 keeps the second input channel 410 connected to the target input channel connected to the first output channel 420. This is beneficial for establishing the signal transmission path of the holding relay 400 synchronously when the first control unit 310 is working normally. When the power supply to the first control unit 310 is abnormal, the holding relay 400 maintains its previous connection state, so that the first output channel 420 continuously outputs the first signal of the target input channel to the second communication device 200. This avoids communication interruption caused by the failure of the first control unit 310, which helps to ensure the continuity of signal transmission between the first communication device 100 and the second communication device 200 and improves the reliability of the entire communication system.

[0036] In some embodiments, the holding relay 400 is a magnetic holding relay 400.

[0037] In some embodiments, both the first communication device 100 and the second communication device 200 are protection devices.

[0038] In some embodiments, a power supply abnormality refers to the first control unit 310 being in at least one of passive power supply, power failure, power outage, or power loss.

[0039] In some embodiments of this application, the first control unit 310 selects the one with better first signal quality from at least two first input channels 320 as the target input channel.

[0040] It should be explained that signal quality is an indicator used to measure the stability and integrity of the first signal transmission. The first control unit 310 selects a better transmission path from at least two first input channels 320 by judging this indicator.

[0041] It is understandable that the setting of the first control unit 310 selecting the one with better first signal quality from at least two first input channels 320 as the target input channel helps to ensure that the signal transmission between the first communication device 100 and the second communication device 200 is in a more stable and reliable state, and reduces transmission errors or interruptions caused by poor signal quality.

[0042] In some embodiments of this application, please refer to Figure 2 , Figure 2A schematic diagram of the framework structure of the channel switching circuit provided in this embodiment is shown. The channel switching circuit of this embodiment includes a first relay 500, the output terminal of which is used to connect to the second communication device 200. The first relay 500 has a first reset state and a first set state. In the first reset state, the first relay 500 is connected to the second output channel of the holding relay 400. In the first set state, the first relay 500 is connected to the first signal of the first control unit 310. When the first control unit 310 is powered normally, the first relay 500 switches to the first set state. When the first control unit 310 is powered abnormally, the first relay 500 switches to the first reset state.

[0043] It is understandable that the use of a channel switching circuit, including the setting of a first relay 500, with the first relay 500 having a first reset state and a first set state, facilitates automatic switching of the signal transmission path. When the first control unit 310 is powered normally, the first relay 500 switches to the first set state, connecting to the first signal of the first control unit 310, ensuring that the signal is transmitted after being processed by the first control unit 310 under normal operating conditions, thus guaranteeing the controllability and specificity of signal transmission; when the first control unit 310 is powered abnormally, the first relay 500 switches to the first reset state, connecting to the second output channel of the holding relay 400, allowing the signal to be maintained through the holding relay 400 for transmission.

[0044] In some embodiments, the first relay 500 is a monostable relay.

[0045] In some embodiments of this application, the first control unit 310 is used to switch the first relay 500 from a first reset state to a first set state.

[0046] Understandably, using the first control unit 310 to switch the first relay 500 from the first reset state to the first set state facilitates active control of the state transition of the first relay 500 when the first control unit 310 is powered normally. When the device is powered on and the first control unit 310 is working normally, it drives the first relay 500 to switch from the initial first reset state to the first set state through the output control signal, switching the signal transmission path to the first control unit 310 side. This ensures that the first signal can be transmitted to the second communication device 200 after being processed by the first control unit 310, guaranteeing the controllability and effectiveness of signal transmission under normal operating conditions. This state switching dominated by the first control unit 310 not only conforms to the control logic when the device is working normally, but also reserves a logical basis for the automatic reset of the first relay 500 to the first reset state (connecting to the path of the holding relay 400) when the power supply is abnormal. It realizes the orderly transition between the two working states, further ensuring the continuity of signal transmission under different power supply scenarios and improving the reliability of the channel switching circuit.

[0047] In some embodiments, the first control unit 310 is an FPGA (Field-Programmable Gate Array).

[0048] In some embodiments of this application, please refer to Figure 3 , Figure 3 A schematic diagram of the circuit structure of the channel switching circuit provided in this embodiment is shown; as follows: Figure 3 As shown, this embodiment uses a 2M channel switching device A as the channel switching circuit, the first control unit 310 and the second control unit as FPGAs, the first communication device 100 as protection device B, the second communication device 200 as protection device A, the holding relay 400 as K1, and the first relay 500 as K2 as an example. The channel switching circuit of this embodiment also includes a second signal transmission channel 600, which is used to access the second signal of the second communication device 200. The second signal transmission channel 600 has at least two second output channels, and at least two second output channels are used to output the second signal of the second communication device to the first communication device. The first communication device outputs a first signal based on the second signal.

[0049] It is understandable that the inclusion of a second signal transmission channel 600 in the channel switching circuit, with at least two second output channels, facilitates bidirectional signal transmission between the first communication device 100 and the second communication device 200. The second signal transmission channel 600 receives the second signal from the second communication device 200 and transmits it to the first communication device 100 through at least two second output channels, enabling the first communication device 100 to output a corresponding first signal based on the second signal, forming a complete signal interaction closed loop. This bidirectional transmission configuration not only meets the information interaction requirements between the two communication devices but also, in conjunction with components such as the first signal transmission channel 300 and the holding relay 400, ensures the continuity of the first signal transmission while guaranteeing the stable transmission of the second signal. This maintains the reliability of bidirectional communication regardless of whether the power supply is normal or abnormal, further enhancing the adaptability of the channel switching circuit in complex communication scenarios.

[0050] In some embodiments, the second signal is a transmitting signal and the first signal is a receiving signal.

[0051] Please refer to the embodiments described in this application. Figure 3 In this embodiment, a second control unit is provided on the second signal transmission channel 600. The second control unit is used to select one of at least two second output channels to output a second signal.

[0052] Understandably, the arrangement of a second control unit on the second signal transmission channel 600, whereby the second control unit selects one of at least two second output channels to output the second signal, facilitates flexible channel selection during the second signal transmission process. When the device is powered normally, the second control unit can selectively choose the optimal second output channel based on the characteristics of the second signal (such as signal quality and transmission requirements), ensuring efficient and stable transmission of the second signal to the first communication device 100, thus providing a reliable basis for the first communication device 100 to output the first signal based on the second signal.

[0053] In some embodiments, the second control unit is an FPGA (Field-Programmable Gate Array).

[0054] Please refer to the embodiments described in this application. Figure 3In this embodiment, taking K3A and K3B as the second relays as an example, the channel switching circuit of this embodiment also includes at least two second relays. The second relays have a second reset state and a second set state. In the second reset state, the second relays are connected to the second signal of the second communication device and output the second signal to the first communication device. In the second set state, the second relays are connected to the second signal of the corresponding second output channel and output the second signal to the first communication device.

[0055] It is understandable that the channel switching circuit includes at least two second relays, each with a second reset state and a second set state, which facilitates flexible switching of the second signal transmission path. When the second control unit is operating normally, the second relays can be driven to the second set state, allowing the second signal to be transmitted through the selected second output channel, ensuring the targeted and controllable transmission of the second signal under normal operating conditions. When a power supply failure causes the second control unit to malfunction, the second relays can switch to the second reset state, directly connecting to the second signal of the second communication device 200 and outputting it to the first communication device 100, preventing interruption of the second signal transmission due to control unit failure.

[0056] Please refer to the embodiments described in this application. Figure 3 In this embodiment, the third relay is K4 as an example. The channel switching circuit of this embodiment also includes a third relay. The third relay is used to receive the second signal from the second communication device 200, and is used to transmit the second signal to the second control unit when the power supply to the second control unit is normal, and to transmit the second signal to the second relay when the power supply to the second control unit is abnormal.

[0057] It is understandable that the use of a channel switching circuit, including the inclusion of a third relay, and the third relay being used to receive the second signal from the second communication device 200, facilitates the accurate transmission of the second signal under different power supply conditions. When the second control unit is powered normally, the third relay transmits the second signal to the second control unit, enabling the second control unit to select the appropriate second output channel based on the second signal, ensuring the controllability and optimization of the second signal transmission under normal operating conditions. When the second control unit is powered abnormally, the third relay directly transmits the second signal to the second relay, ensuring that the second signal can be continuously transmitted to the first communication device 100 through the corresponding state of the second relay (second reset state or second set state), avoiding interruption of the second signal transmission due to failure of the second control unit.

[0058] In some embodiments of this application, the first control unit 310 and the second control unit are reused.

[0059] It should be explained that reuse means that the first control unit 310 and the second control unit share the same physical unit. This unit simultaneously undertakes the functions that were originally performed by the two independent control units. That is, it is responsible for both the selection and related control of the target input channel in the first signal transmission channel 300 and the selection and related control of the second output channel in the second signal transmission channel 600.

[0060] Understandably, the reuse of the first control unit 310 and the second control unit simplifies the overall structure of the channel switching circuit. By having the same control unit simultaneously handle the transmission control logic of the first and second signals, the number of independent control units is reduced, lowering circuit complexity and hardware costs. Simultaneously, it facilitates unified coordination of the operating states of the first signal transmission channel 300 and the second signal transmission channel 600, improving the consistency of circuit control. When the device is powered normally, the reused control unit can simultaneously manage the selection of the first input channel 320, the control of the holding relay 400, and the selection of the second output channel, as well as the driving of the second and third relays, ensuring the orderly transmission of bidirectional signals. In the event of a power outage, although the reused control unit stops working, the state maintenance or automatic reset characteristics of the holding relays 400, the second relay, and the third relay can still maintain continuous bidirectional signal transmission. This reuse setup, while ensuring communication reliability, optimizes circuit integration and better suits the design requirements of miniaturization and lightweight devices.

[0061] Furthermore, in order to better implement the channel switching circuit in any of the above embodiments, please continue to refer to the following based on the channel switching circuit described above. Figure 3 This application also provides an electronic device, including at least one channel switching circuit as described above. When there are at least two channel switching circuits, the at least two channel switching circuits are connected in series.

[0062] It is understandable that the two channel switching circuits can be set symmetrically, such as... Figure 3 The 2M channel switching device A and 2M channel switching device B in the system ensure that the transmission and reception signals of protection device A and protection device B each have only one signal.

[0063] In some embodiments of this application, the electronic device further includes a first communication device 100, which is used to receive a second signal output by the channel switching circuit and output a first signal to the first communication device 100 based on the second signal.

[0064] In some embodiments of this application, the electronic device further includes a second communication device 200, which is used to output a second signal to the channel switching circuit and to receive a first signal output by the channel switching circuit.

[0065] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0066] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0067] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0068] Similarly, it should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the application requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0069] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A channel switching circuit, characterized in that, The channel switching circuit, positioned between the first communication device and the second communication device, includes: A first signal transmission channel is provided with a first control unit. The first signal transmission channel has at least two first input channels. The at least two first input channels are used to access the first signal of the first communication device. The first control unit is used to select one of the at least two first input channels as a target input channel based on the first signal, and is used to transmit the first signal of the target input channel to the second communication device. A holding relay has a first output channel and at least two second input channels, the second input channels being connected to the first input channel and used to acquire the first signal; the first control unit is used to keep the second input channel connected to the target input channel connected to the first output channel. In the event of a power supply failure in the first control unit, the first output channel outputs the first signal of the target input channel to the second communication device.

2. The channel switching circuit according to claim 1, characterized in that, The first control unit selects the one with better first signal quality from at least two first input channels as the target input channel.

3. The channel switching circuit according to claim 2, characterized in that, The channel switching circuit includes a first relay, the output of which is used to connect to the second communication device; the first relay has a first reset state and a first set state, in the first reset state, the first relay is connected to the second output channel of the holding relay, and in the first set state, the first relay is connected to the first signal of the first control unit; When the first control unit is powered normally, the first relay switches to the first set state; when the first control unit is powered abnormally, the first relay switches to the first reset state.

4. The channel switching circuit according to claim 3, characterized in that, The first control unit is used to switch the first relay from the first reset state to the first set state.

5. The channel switching circuit according to claim 1, characterized in that, The channel switching circuit further includes a second signal transmission channel, which is used to access the second signal of the second communication device; The second signal transmission channel has at least two second output channels, each of which is used to output a second signal from the second communication device to the first communication device, and the first communication device outputs the first signal based on the second signal.

6. The channel switching circuit according to claim 5, characterized in that, A second control unit is provided on the second signal transmission channel. The second control unit is used to select one of the at least two second output channels to output the second signal.

7. The channel switching circuit according to claim 6, characterized in that, The channel switching circuit further includes at least two second relays, each having a second reset state and a second set state. In the second reset state, the second relay receives the second signal from the second communication device and outputs the second signal to the first communication device. In the second set state, the second relay receives the second signal from the corresponding second output channel and outputs the second signal to the first communication device.

8. The channel switching circuit according to claim 7, characterized in that, The channel switching circuit further includes a third relay, which is used to receive a second signal from the second communication device and to transmit the second signal to the second control unit when the second control unit is powered normally, and to transmit the second signal to the second relay when the second control unit is powered abnormally.

9. An electronic device, characterized in that, It includes at least one channel switching circuit as described in any one of claims 1 to 8, wherein if there are at least two channel switching circuits, the at least two channel switching circuits are connected in series.

10. The electronic device according to claim 9, characterized in that, The electronic device further includes a first communication device and a second communication device. The first communication device is used to receive a second signal output by the channel switching circuit and output a first signal to the first communication device based on the second signal. The second communication device is used to output a second signal to the channel switching circuit and to receive the first signal output by the channel switching circuit.

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