Control System, Its Control Method, and Computer-Readable Storage Medium

Abstract

The present disclosure provides a control system, a control method thereof, and a computer-readable storage medium. The control system includes: a main controller, a standby controller, and a plurality of expansion modules. The plurality of expansion modules include at least one main expansion module and a corresponding at least one standby expansion module. The plurality of expansion modules are connected to the main controller and the standby controller through an expansion bus. Each expansion module is connected to a field protocol device through a device connection line; the main controller is configured to perform data reading and writing operations on the field protocol device through the expansion bus and the main expansion module; the standby controller is configured to receive data from the expansion bus and not send control data to the expansion bus; the main expansion module is configured to receive data from the expansion bus and send data to the expansion bus; the standby expansion module is configured to receive data from the expansion bus and not send data to the expansion bus.

Description

Technical Field

[0001] The present disclosure relates to the field of building control technology, and in particular to a control system and a control method thereof, and a computer-readable storage medium. Background Art

[0002] In building control systems, equipment, communications, and software failures are inevitable during long-term operation, and the system is in a downtime state. In related technologies, dual-controller solutions are used, and the main and standby controllers are generally connected in parallel to the bus, and the system process data is synchronized through a dedicated data synchronization interface. With this system redundancy, once the data synchronization line is abnormal, there will be two hosts in the control system at the same time. When two hosts request the device bus at the same time, it will cause abnormal communication between the controller and the device, resulting in abnormal system data. Summary of the invention

[0003] A technical problem solved by the present disclosure is to provide a control system to prevent the problem of abnormal system data as much as possible.

[0004] According to one aspect of the present disclosure, a control system is provided, including: a main controller, a standby controller and a plurality of expansion modules, the plurality of expansion modules including at least one main expansion module and a corresponding at least one standby expansion module, the plurality of expansion modules being connected to the main controller and the standby controller via an expansion bus, and each expansion module being connected to a field protocol device via a device connection line; the main controller being used to perform data read and write operations on the field protocol device via the expansion bus and the main expansion module; the standby controller being used to receive data from the expansion bus and not to send control data to the expansion bus; the main expansion module being used to receive data from the expansion bus and to send data to the expansion bus; and the standby expansion module being used to receive data from the expansion bus and not to send data to the expansion bus.

[0005] In some embodiments, the main controller is also used to send a redundant heartbeat request signal to the backup controller at intervals of a first time period; the backup controller is also used to return a redundant heartbeat response signal to the main controller within the first time period after receiving the redundant heartbeat request signal, so as to establish a heartbeat link with the main controller.

[0006] In some embodiments, the primary expansion module and the corresponding standby expansion module have the same address, and the primary expansion module and the standby expansion module having the same address are linked to the same field protocol device.

[0007] In some embodiments, the multiple expansion modules include a first expansion module, and the first expansion module is used to broadcast an address broadcast frame including its own address to the expansion bus after a random time has passed. If no redundant host response frame is received from the expansion module with the same address within a predetermined time, or an address broadcast frame is received from the expansion module with the same address within the predetermined time, the first expansion module itself is determined to be a main expansion module; if the redundant host response frame is received within the predetermined time, the first expansion module itself is determined to be a standby expansion module, wherein the predetermined time is greater than the random time.

[0008] In some embodiments, the main controller is used to publish the data from the field protocol device to the proxy server module in the main controller; the standby controller is used to receive a subscription message sent by the proxy server module to obtain the data of the field protocol device, wherein the subscription message contains the data of the field protocol device.

[0009] In some embodiments, the main controller is used to send a data read request to the field protocol device; the field protocol device is used to output response data in the form of a differential voltage to the expansion bus after receiving the data read request; wherein the main controller and the standby controller detect changes in the expansion bus voltage to obtain the response data.

[0010] In some embodiments, the main controller is used to send an extended heartbeat request signal to the multiple expansion modules; at least one expansion module among the multiple expansion modules is used to return an extended heartbeat response signal to the main controller after receiving the extended heartbeat request signal from the expansion bus, so as to establish a heartbeat link with the main controller.

[0011] In some embodiments, the control system further includes: a monitoring server, which is communicatively connected to the main controller and the standby controller respectively, and is used to obtain fault information of the main controller, the standby controller or the main expansion module.

[0012] In some embodiments, if the standby controller does not receive a redundant heartbeat request signal and an extended heartbeat request signal from the main controller within the first time period, it determines that the main controller has failed, autonomously switches to the main controller mode, removes communication restrictions, initiates read and write control to the on-site protocol device, and reports information that it has switched to the main controller mode to the monitoring server.

[0013] In some embodiments, the main controller is also used to determine that the standby controller has failed if no redundant heartbeat response signal and extended heartbeat response signal of the standby controller are received within the first time period, and report the failure information of the standby controller to the monitoring server.

[0014] In some embodiments, the main controller is used to send an expansion heartbeat request signal to the multiple expansion modules. If no expansion heartbeat response signal is received from the main expansion module within a second time period, it is determined that the main expansion module has a fault, and the information that the main expansion module has a fault is reported to the monitoring server; the standby expansion module with the same address as the main expansion module is also used to determine that the main expansion module has a fault if no expansion heartbeat response signal is received from the main expansion module within the second time period, and autonomously switch to the main expansion module.

[0015] In some embodiments, the main controller is also used to send the local files of the main controller to the standby controller after power-on; the standby controller is also used to compare the local files of the standby controller with the local files of the main controller, and if the local files of the standby controller are inconsistent with the local files of the main controller, synchronize the local files of the main controller to the standby controller.

[0016] In some embodiments, the main controller and the standby controller are respectively provided with a first indicator light panel, and the first indicator light panel includes: a first operation mode indicator light, used to indicate that the current controller is in a redundant operation mode; a first data sending indicator light, used to indicate that the current controller sends data through a device bus, wherein the main controller and the standby controller are connected to a switch through the device bus, and the switch is communicatively connected to the field protocol device; a first data receiving indicator light, used to indicate that the current controller receives data through the device bus; a second data sending indicator light, used to indicate that the current controller sends data through the expansion bus; a second data receiving indicator light, used to indicate that the current controller receives data through the expansion bus; and a first heartbeat link indicator light, used to indicate that the current controller implements a heartbeat link.

[0017] In some embodiments, each expansion module is provided with a second indicator light panel, and the second indicator light panel includes: a second operating mode indicator light, used to indicate that the current expansion module is in a redundant operating mode; a third data sending indicator light, used to indicate that the current expansion module sends data; a third data receiving indicator light, used to indicate that the current expansion module receives data; and a second heartbeat link indicator light, used to indicate that the current expansion module implements a heartbeat link.

[0018] According to another aspect of the present disclosure, a control method for a control system is provided, comprising: a main controller sends a redundant heartbeat request signal to a standby controller at intervals of a first time period; and after receiving the redundant heartbeat request signal, the standby controller returns a redundant heartbeat response signal to the main controller within the first time period, so as to establish a heartbeat link with the main controller.

[0019] In some embodiments, the multiple expansion modules include a first expansion module; the control method further includes: the first expansion module broadcasts an address broadcast frame including its own address to the expansion bus after a random time; if no redundant host response frame is received from an expansion module with the same address within a predetermined time, or an address broadcast frame is received from an expansion module with the same address within the predetermined time, determining that the first expansion module itself is a main expansion module; and if the redundant host response frame is received within the predetermined time, determining that the first expansion module itself is a standby expansion module, wherein the predetermined time is greater than the random time.

[0020] In some embodiments, the control method also includes: the main controller publishes the data from the field protocol device to the proxy server module in the main controller; and the standby controller receives a subscription message sent by the proxy server module to obtain the data of the field protocol device, wherein the subscription message contains the data of the field protocol device.

[0021] In some embodiments, the control method further includes: the main controller sends a data read request to the field protocol device; the field protocol device outputs response data in the form of a differential voltage to the expansion bus after receiving the data read request; and the main controller and the standby controller detect changes in the expansion bus voltage to obtain the response data.

[0022] In some embodiments, the control method also includes: the main controller sends an expansion heartbeat request signal to the multiple expansion modules; and after receiving the expansion heartbeat request signal from the expansion bus, at least one expansion module among the multiple expansion modules returns an expansion heartbeat response signal to the main controller to establish a heartbeat link with the main controller.

[0023] In some embodiments, the control method also includes: if the standby controller does not receive the redundant heartbeat request signal and the extended heartbeat request signal from the main controller within the first time period, it determines that the main controller has failed, autonomously switches to the main controller mode, lifts the communication restrictions, initiates read and write control to the on-site protocol device, and reports the information that it has switched to the main controller mode to the monitoring server.

[0024] In some embodiments, the control method also includes: if the main controller does not receive the redundant heartbeat response signal and extended heartbeat response signal of the standby controller within the first time period, it determines that the standby controller has failed, and reports the information that the standby controller has failed to the monitoring server.

[0025] In some embodiments, the control method further includes: the main controller sends an expansion heartbeat request signal to the multiple expansion modules, and if no expansion heartbeat response signal is received from the main expansion module within a second time period, determines that the main expansion module fails, and reports the information that the main expansion module fails to a monitoring server; and if a standby expansion module with the same address as the main expansion module does not receive an expansion heartbeat response signal from the main expansion module within the second time period, determines that the main expansion module fails, and autonomously switches to the main expansion module.

[0026] In some embodiments, the control method also includes: after the main controller is powered on, sending the local file of the main controller to the standby controller; and the standby controller comparing the local file of the standby controller with the local file of the main controller, and if the local file of the standby controller is inconsistent with the local file of the main controller, synchronizing the local file of the main controller to the standby controller.

[0027] According to another aspect of the present disclosure, a control system is provided, including: a memory; and a processor coupled to the memory, wherein the processor is configured to execute the aforementioned method based on instructions stored in the memory.

[0028] According to another aspect of the present disclosure, a computer-readable storage medium is provided, on which computer program instructions are stored. When the computer program instructions are executed by a processor, the method described above is implemented.

[0029] In the above control system, when a main expansion module fails, the standby expansion module can go online and enter a working state, thereby preventing the problem of system data abnormality as much as possible.

[0030] Other features and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0032] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0033] Figure 1 is a block diagram schematically illustrating a control system according to some embodiments of the present disclosure;

[0034] Figure 2 is a schematic diagram schematically illustrating a first indicator light panel of a controller according to some embodiments of the present disclosure;

[0035] Figure 3 is a schematic diagram schematically illustrating a second indicator light panel of an expansion module according to other embodiments of the present disclosure;

[0036] Figure 4 is a block diagram schematically illustrating a control system according to some other embodiments of the present disclosure;

[0037] Figure 5 is a schematic diagram schematically illustrating a bus deployment mechanism of a control system according to some embodiments of the present disclosure;

[0038] Figure 6 is a redundancy detection logic diagram schematically showing a main controller and a standby controller of a control system according to some embodiments of the present disclosure;

[0039] Figure 7 is a flow chart illustrating a control method for controlling a system according to some embodiments of the present disclosure;

[0040] Figure 8 is a flow chart showing a control method for controlling a system according to other embodiments of the present disclosure;

[0041] Fig. 9 is a block diagram schematically illustrating a control system according to some other embodiments of the present disclosure;

[0042] Fig.10 is a block diagram schematically illustrating a control system according to some other embodiments of the present disclosure. DETAILED DESCRIPTION

[0043] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure unless otherwise specifically stated.

[0044] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0045] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0046] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0047] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0048] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0049] Figure 1 is a block diagram schematically illustrating a control system according to some embodiments of the present disclosure.

[0050] like Figure 1 As shown, the control system includes: a main controller 110, a standby controller 120 and a plurality of expansion modules. The plurality of expansion modules include at least one main expansion module (for example, n main expansion modules, n is a positive integer) and at least one corresponding standby expansion module (for example, n standby expansion modules). The plurality of expansion modules are connected to the main controller 110 and the standby controller 120 via an expansion bus 101. Here, the expansion bus 101 includes a communication line of the expansion bus (which may be referred to as an expansion communication line). Each expansion module is connected to a field protocol device (for example, field protocol device 1, field protocol device 2...) via a device connection line 103. For example, the main controller 110 may be connected to the standby controller 120 via a redundant communication line 102.

[0051] The main controller 110 is used to perform data read and write operations on the field protocol device through the expansion bus 101 and the main expansion module. For example, the main controller 110 sends control data to the expansion bus 101, and the main expansion module transmits the control data to the corresponding field protocol device to implement the data write operation of the main controller 110; or, the field protocol device sends device data to the main expansion module, and the main expansion module transmits the device data to the main controller 110 through the expansion bus, so that the main controller 110 implements the data read operation. For example, the main controller 110 is a soft redundant programmable controller.

[0052] The standby controller 120 is used to receive data from the expansion bus and not send control data to the expansion bus. For example, the standby controller 120 limits the function of sending control data, but can send a response signal in response to the heartbeat request of the expansion bus and retain the function of receiving data. For example, the standby controller 120 is a soft redundant programmable controller.

[0053] The main expansion module is used to receive data from the expansion bus and send data to the expansion bus. That is, the main expansion module can realize the reception and transmission of data.

[0054] The standby expansion module is used to receive data from the expansion bus and not to send data to the expansion bus. That is, the standby expansion module can receive data but cannot send data.

[0055] So far, a control system according to some embodiments of the present disclosure is provided. The control system includes: a main controller, a standby controller and a plurality of expansion modules, the plurality of expansion modules include at least one main expansion module and at least one corresponding standby expansion module, the plurality of expansion modules are connected to the main controller and the standby controller through an expansion bus, and each expansion module is connected to a field protocol device through a device connection line; the main controller is used to read and write data to the field protocol device through the expansion bus and the main expansion module; the standby controller is used to receive data from the expansion bus and not send data to the expansion bus; the main expansion module is used to receive data from the expansion bus and send data to the expansion bus; the standby expansion module is used to receive data from the expansion bus and not send data to the expansion bus. In this control system, by setting a standby expansion module, when the main expansion module fails, the standby expansion module can go online and enter the working state, thereby preventing the problem of abnormal system data as much as possible. Moreover, the above control system can solve the problem of unit redundancy module singularity and insufficient switching stability in the control system as much as possible.

[0056] Optionally, the control system may further include the field protocol device. Of course, the scope of the present disclosure is not limited thereto, for example, the control system may not include the field protocol device.

[0057] In some embodiments, the main expansion module and the corresponding standby expansion module have the same address. The main expansion module and the standby expansion module with the same address are linked to the same field protocol device. Here, the addresses of the main expansion module and the standby expansion module are consistent. When the main expansion module fails, there is no need to modify the address of the standby expansion module. The standby expansion module can automatically go online and enter the working state, and the system can continue to operate normally. Only the failed expansion module needs to be repaired later, so that the control system can operate flexibly and efficiently.

[0058] In some embodiments, the main controller 110 and the standby controller 120 are respectively provided with a first indicator light panel. Figure 2 The first indicator light panel 200 is described. Figure 2 is a schematic diagram schematically illustrating a first indicator light panel of a controller according to some embodiments of the present disclosure.

[0059] like Figure 2As shown, the first indicator panel 200 includes: a first operating mode indicator light STAT_1, a first data sending indicator light TX_1, a first data receiving indicator light RX_1, a second data sending indicator light TX_2, a second data receiving indicator light RX_2 and a first heartbeat link indicator light BEAT_1.

[0060] The first operation mode indicator STAT_1 is used to indicate that the current controller is in a redundant operation mode.

[0061] The first data transmission indicator TX_1 is used to indicate that the current controller sends data through the device bus. Here, the main controller and the standby controller are connected to the switch through the device bus, and the switch is connected to the field protocol device (which will be combined later). Figure 4 describe).

[0062] The first data receiving indicator light RX_1 is used to indicate that the current controller (main controller or standby controller) receives data through the device bus.

[0063] The second data sending indicator light TX_2 is used to indicate that the current controller sends data through the expansion bus.

[0064] The second data receiving indicator light RX_2 is used to indicate that the current controller receives data through the expansion bus.

[0065] The first heartbeat link indicator BEAT_1 is used to indicate that the current controller implements a heartbeat link.

[0066] In some embodiments, each expansion module is provided with a second indicator light panel. Figure 3 The second indicator light panel 300 is described. Figure 3 is a schematic diagram schematically illustrating a second indicator light panel of an expansion module according to some other embodiments of the present disclosure.

[0067] like Figure 3 As shown, the second indicator panel 300 includes: a second operation mode indicator light STAT_2, a third data sending indicator light TX_3, a third data receiving indicator light RX_3 and a second heartbeat link indicator light BEAT_2.

[0068] The second operation mode indicator STAT_2 is used to indicate that the current expansion module (a main expansion module or a standby expansion module) is in a redundant operation mode.

[0069] The third data sending indicator light TX_3 is used to indicate that the current expansion module is sending data.

[0070] The third data receiving indicator light RX_3 is used to indicate that the current expansion module is receiving data.

[0071] The second heartbeat link indicator BEAT_2 is used to indicate that the current expansion module implements a heartbeat link.

[0072] In an embodiment of the present disclosure, the indicator light can be an LED (Light Emitting Diode) lamp.

[0073] In the above embodiment, the indicator light panels of the controller and the expansion module can indicate their current operating states. Of course, those skilled in the art can understand that the above indicator light panels can also be replaced by components with display functions such as embedded displays, mobile phone APPs (applications), web pages, etc. Therefore, the scope of the present disclosure is not limited thereto.

[0074] In some embodiments, the main controller 110 can also be used to send a redundant heartbeat request signal to the standby controller 120 every first time period T1. The standby controller 120 can also be used to return a redundant heartbeat response signal to the main controller 110 within the first time period (i.e., at a certain moment, where the time elapsed to reach this moment is less than the first time period) after receiving the redundant heartbeat request signal, so as to establish a heartbeat link with the main controller 110. For example, the range of the first time period T1 can be 0 < T1 ≤ 2 seconds. Of course, the scope of the present disclosure is not limited thereto.

[0075] For example, when the control system for a building is operating normally, the main controller 110 maintains a redundant heartbeat and data synchronization connection with the standby controller 120 through a redundant communication line. The main controller 110 sends a redundant heartbeat request signal to the standby controller 120 every first time period T1, and the standby controller 120 needs to reply to the main controller 110 before the first time period arrives. At this time, the first heartbeat link indicator BEAT_1 of both parties flashes normally. The main controller 110 communicates with the field devices through the device bus and the expansion bus, and normally performs read and write control. Its two groups of TX and RX lights (i.e., the first data transmission indicator TX_1, the first data reception indicator RX_1, the second data transmission indicator TX_2, and the second data reception indicator RX_2) flash normally. The standby controller 120 restricts the function of sending control data, but can send a response signal in response to the heartbeat request of the expansion bus, and at the same time retains the function of receiving data. Its TX_1 and RX_1 lights are both in the off state, and TX_2 and RX_2 flash normally. At this time, the normal flashing of TX_2 can indicate that the standby controller can send a redundant heartbeat response signal.

[0076] In some embodiments, the plurality of expansion modules include a first expansion module, the first expansion module being used to broadcast an address broadcast frame containing its own address to the expansion bus after a random time has passed, and if no redundant host response frame is received from an expansion module with the same address within a predetermined time, or an address broadcast frame is received from an expansion module with the same address within the predetermined time, the first expansion module itself is determined to be a main expansion module; if a redundant host response frame is received within a predetermined time, the first expansion module itself is determined to be a standby expansion module, wherein the predetermined time is greater than the random time. Here, the first expansion module is any one of the plurality of expansion modules.

[0077] It should be noted that the above random time can be understood as a random time within a predetermined range, for example, not exceeding 1 second, in order to prevent the main and standby expansion modules from sending data at the same time during the system initialization phase, so that there is a sequence and it is convenient for logical judgment. The above predetermined time can be set according to actual needs. The above redundant host refers to the position of the main expansion module in the redundant mode of a certain expansion module, therefore, the expansion module that sends the redundant host response frame is the main expansion module.

[0078] In the above embodiment, in order to make the control system run flexibly and efficiently, the addresses of the two expansion modules remain consistent, and their master-slave relationship requires autonomous competition and confirmation between the two modules with the same address through address broadcast frames.

[0079] For example, after the system is powered on, all the indicator lights in the light board of the expansion module are off, and after establishing a heartbeat link with the main controller, the second heartbeat link indicator light BEAT_2 of the expansion module turns to be always on. In some embodiments, the main controller is used to send an expansion heartbeat request signal to the multiple expansion modules; at least one expansion module among the multiple expansion modules is used to return an expansion heartbeat response signal to the main controller after receiving the expansion heartbeat request signal from the expansion bus, so as to establish a heartbeat link with the main controller. In this way, the expansion module establishes a heartbeat link with the main controller.

[0080] After a random delay time T0, a certain expansion module (i.e., the first expansion module) broadcasts a data frame containing its own address (i.e., an address broadcast frame) to the expansion bus. If it does not receive a redundant host response frame with the same address within a predetermined time (or called a timeout time) (indicating that other expansion modules with the same address are not currently serving as the main expansion module), or receives an address broadcast frame from a module with the same address within a predetermined time (the predetermined time is greater than the random time) (indicating that the time when other expansion modules with the same address send address broadcast frames is later than the time when this expansion module sends address broadcast frames), then the first expansion module confirms itself as the main expansion module, turns the second operation mode indicator STAT_2 to be always on, and broadcasts a redundant host response frame to the expansion bus. Other expansion modules with the same address that receive the redundant host response frame are confirmed as standby expansion modules, and their second operation mode indicator STAT_2 remains always off.

[0081] The main expansion module can read and write the field protocol equipment normally and respond to the heartbeat request of the main controller. The status of its light board is that the second operation mode indicator STAT_2 and the second heartbeat link indicator BEAT_2 are always on, and the third data sending indicator TX_3 and the third data receiving indicator RX_3 are flashing; the standby expansion module does not need to respond to the heartbeat request, cannot send data to the field protocol equipment, and only retains the function of receiving data. The status of its light board is that the second operation mode indicator STAT_2 and the third data sending indicator TX_3 remain always off, the third data receiving indicator RX_3 flashes, and the second heartbeat link indicator BEAT_2 is always on.

[0082] In some embodiments, the main controller 110 is used to publish data from the field protocol device to the proxy server module in the main controller. The standby controller 120 is used to receive a subscription message sent by the proxy server module to obtain the data of the field protocol device, wherein the subscription message contains the data of the field protocol device. This embodiment enables the controller to obtain device data based on a request-response communication mechanism.

[0083] In other embodiments, the main controller 110 is used to send a data read request to a field protocol device (e.g., field protocol device 1). The field protocol device is used to output response data in the form of a differential voltage to the expansion bus 101 after receiving the data read request. The main controller 110 and the standby controller 120 detect the change in the expansion bus voltage to obtain the response data. This embodiment enables the controller to obtain device data based on differential signal detection logic.

[0084] In the above described embodiment, when the system is operating normally, the master and standby controllers are always performing data synchronization. In order to reduce the communication pressure of controller data synchronization, two different methods can be used to cooperate with synchronization: ① Device data based on request-response communication mechanism: For such data, the master and standby controllers use a subscription / publishing communication mechanism to achieve data synchronization. The master controller will publish the data change value from such devices (for example, BACnet devices or TCP / IP (Transmission Control Protocol / Internet Protocol, Transmission Control Protocol / Internet Protocol) devices, etc.) to the proxy server module in real time. The standby controller links to the proxy server module and receives the corresponding subscription message, thereby obtaining data from such devices in real time. ② Device data based on differential signal detection logic: After the master controller sends a data read request to such devices (for example, RS485 devices or I / O (input / output) devices, etc.), the device outputs response data in the form of differential voltage to the expansion bus. The master and standby controllers can detect the change of bus voltage at the same time. Therefore, for such data, the standby controller can interpret it by itself without synchronization from the master controller, which reduces the pressure of data synchronization.

[0085] The standby controller of the disclosed embodiment can adopt a dual-channel mechanism to synchronize redundant data, reduce the data transmission pressure of the main controller, and speed up the synchronization of data between the main and standby controllers. This can solve the problem of large resource consumption and slow redundant switching speed when synchronizing redundant data in the control system as much as possible.

[0086] In some embodiments, the main controller 110 can also be used to send the local files of the main controller to the standby controller 120 after power-on. The standby controller 120 can also be used to compare the local files of the standby controller with the local files of the main controller, and synchronize the local files of the main controller to the standby controller when the local files of the standby controller are inconsistent with the local files of the main controller. For example, the local files include local program versions, configuration data, configuration logic and other files. In this way, the verification and synchronization of local files are achieved.

[0087] In order to ensure that the redundant switching of the active and standby controllers is fast and normal, software information synchronization and real-time data synchronization are required between the active and standby controllers. In the above embodiment, when the building control system is powered on, the active and standby controllers actively check the local program version, configuration data, configuration logic and other files. When the verification is inconsistent, the standby controller synchronizes the files corresponding to the active controller to the local.

[0088] Figure 4 is a block diagram schematically illustrating a control system according to some other embodiments of the present disclosure.

[0089] Figure 5The figure schematically shows a bus allocation mechanism of a control system according to some embodiments of the present disclosure. Figure 6 Schematically shows the redundancy detection logic diagram of the main controller and the standby controller of the control system according to some embodiments of the present disclosure. Figures 4 to 6 A control system according to other embodiments of the present disclosure is described in detail.

[0090] like Figure 4 As shown, the control system includes a main controller 110, a standby controller 120 and the plurality of expansion modules.

[0091] In some embodiments, Figure 4 As shown, the main controller 110 and the standby controller 120 are connected to the switch 440 via the device bus 404, and the switch 440 is communicatively connected to the field protocol device. For example, the control system further includes the switch 440.

[0092] In some embodiments, the field protocol device may include a BACnet device, an RS485 device, an I / O device, or a TCP / IP device, etc. Here, a portion of the plurality of field protocol devices (e.g., a BACnet device or a TCP / IP device) may be connected to the main controller 110 and the standby controller 120 via the device bus 404, and another portion of the plurality of field protocol devices (e.g., an RS485 device or an I / O device) may be connected to the main controller 110 and the standby controller 120 via the expansion bus 101.

[0093] For example, Figure 5 As shown, the main controller 110 can read and write data to the field protocol device through the device bus 404 and the expansion bus 101; the standby controller 120 receives data from the field protocol device through the device bus 404 and the expansion bus 101, but does not send data to the device bus 404 and the expansion bus 101. Redundancy switching can be implemented between the main controller 110 and the standby controller 120. For example, when the main controller 110 fails, the standby controller 120 switches to the function of the main controller (i.e., the main controller mode).

[0094] In some embodiments, Figure 4 As shown, the control system may further include a monitoring server 430. The monitoring server 430 is respectively connected to the main controller 110 and the standby controller 120 for communication. For example, the monitoring server 430 is connected to the main controller 110 and the standby controller 120 via a standard network cable 403. The monitoring server 430 is used to obtain fault information of the main controller, the standby controller or the main expansion module. Of course, the monitoring server 430 may also be used to obtain other information, such as information that the standby controller switches to the main controller mode.

[0095] When a system fails, it can be divided into two situations: controller failure and expansion module failure. Controller failure can include main controller failure and standby controller failure. The following describes them separately.

[0096] In some embodiments, if the standby controller 120 does not receive a redundant heartbeat request signal and an extended heartbeat request signal from the main controller within a first time period, it can determine that the main controller has failed, autonomously switch to the main controller mode, remove communication restrictions, initiate read and write control to the on-site protocol device, and report the information that it has switched to the main controller mode to the monitoring server 430.

[0097] The above embodiment realizes the detection of failure of the main controller. Figure 6 As shown, a double redundancy check is performed between the main controller and the standby controller through a redundant communication line and an extended bus (such as an extended communication line) to prevent the occurrence of a dual-master mode. The standby controller simultaneously detects the redundant heartbeat request signal and the extended heartbeat request signal. If the redundant heartbeat request signal and the extended heartbeat request signal from the main controller are not received within the first time period T1, it is determined that the main controller has failed, and the standby controller autonomously switches the host mode (that is, it changes to the main controller mode), removes the communication restrictions of the extended bus and the device bus, initiates read and write control to the field protocol device, and reports the master-slave switching information to the monitoring server.

[0098] In an embodiment of the present disclosure, a redundant heartbeat signal is sent between the main controller and the standby controller to confirm that the redundant communication between the main controller and the standby controller is normal. An extended heartbeat signal is sent to the extension bus, which has the functions of: maintaining the communication connection of the extension module; and confirming that the redundant communication between the main controller and the standby controller is normal. The redundant heartbeat signal and the extended heartbeat signal are based on different communication protocols and use different data frame formats. The main controller can send the redundant heartbeat signal and the extended heartbeat signal respectively through multiple threads.

[0099] In some embodiments, the main controller 110 may also be used to determine that the standby controller 120 has failed if no redundant heartbeat response signal and extended heartbeat response signal from the standby controller are received within a first time period, and report the standby controller failure information to the monitoring server.

[0100] The above embodiment realizes the detection of the failure of the standby controller. In this embodiment, if the main controller receives neither the redundant heartbeat response signal nor the extended heartbeat response signal of the standby controller within the first time period, the main controller determines that the standby controller fails and reports the failure information to the monitoring server.

[0101] In some embodiments, the main controller 110 may be used to send an expansion heartbeat request signal to the plurality of expansion modules. If the expansion heartbeat response signal of the main expansion module is not received within the second time period T2, it is determined that the main expansion module is faulty, and the information that the main expansion module is faulty is reported to the monitoring server 430. The standby expansion module with the same address as the main expansion module may also be used to determine that the main expansion module is faulty if the expansion heartbeat response signal of the main expansion module is not received within the second time period, and autonomously switch to the main expansion module. Here, the second time period may be set according to actual needs.

[0102] This embodiment realizes the detection of failure of the main expansion module. The main controller sends an expansion heartbeat request signal to the expansion module at a fixed time. The main and standby expansion modules can detect the expansion heartbeat request signal at the same time. The standby expansion module does not need to reply to the expansion heartbeat request signal. The main expansion module needs to send an expansion heartbeat response signal within the second time period T2 (which can be called a heartbeat period), otherwise the main controller and the standby expansion module will determine that the main expansion module has failed. At this time, the standby expansion module autonomously switches to the main expansion module. When the expansion module undergoes redundant switching, the standby expansion module will send information to the main controller to inform the main controller that the expansion module at this address has undergone redundant switching. The main controller synchronously reports the information of the failure of the expansion module to the monitoring server. This can solve the problem of needing to shut down for maintenance when any module in the control system fails as much as possible.

[0103] In some embodiments, Figure 4 As shown, the control system may also include a first power supply 451 and a second power supply 452. The first power supply 451 and the second power supply 452 are connected to the main controller 110, the standby controller 120, the main expansion modules 1 to n and the standby expansion modules 1 to n via a power supply line 405. The first power supply 451 and the second power supply 452 are independently powered. Here, the power supply line 405 may be a separate power supply line, or may be part of an extension bus (which may be referred to as an extension power supply line), and the scope of the present disclosure is not limited thereto. When the power supply line 405 is also part of an extension bus, the extension bus may include an extension communication line and the extension power supply line.

[0104] So far, a control system according to other embodiments of the present disclosure is provided. The control system can be used as a building control system. The control system can be divided into a three-layer architecture of "business layer-data processing layer-data acquisition layer", including a monitoring server, a controller, an expansion module, a field protocol device, etc. In the control system, at least two controllers and two sets of expansion modules can be set to achieve the purpose of one for use and one for backup. The main controller and the backup controller are linked by a high-speed redundant communication line. The main and backup controllers and the main and backup expansion modules are connected to the same expansion bus. The main and backup controllers are linked to the same field protocol device, and the expansion modules with the same address are linked to the same field protocol device.

[0105] The control system above realizes the autonomous switching of the building controller when a fault occurs, so that the building control system can run uninterruptedly, reducing the operation and maintenance costs and lowering the technical threshold; the software redundancy of the main and standby controllers is adopted to avoid the system being simplistic and improve the system stability, reliability and security of the building control system. Moreover, the standby controller adopts a dual-channel synchronous redundant data mechanism to reduce the data transmission pressure of the main controller and speed up the data synchronization of the main and standby controllers.

[0106] In addition to deploying redundant communication lines between the main controller and the standby controller, they are also connected to the expansion bus in parallel. After the main controller and the standby controller are operating normally, when both parties maintain a redundant heartbeat link through the redundant communication line, the heartbeat link indicator lights of both parties will flash normally. The main and standby controllers use redundant communication lines and the expansion bus for bidirectional high-reliability redundancy detection to prevent the occurrence of dual-master or masterless modes.

[0107] In some embodiments, the master controller and the standby controller synchronously perform a heartbeat link detection on the expansion bus. For example, the detection includes: removing all expansion modules on the expansion bus, at which time there is no expansion module data on the bus, only the heartbeat check of the master and standby controllers, and the second data sending indicator TX_2 and the second data receiving indicator RX_2 of the master and standby controllers still flash normally.

[0108] Figure 7 is a flow chart showing a control method for controlling a system according to some embodiments of the present disclosure. Figure 7 As shown, the control method includes steps S702 to S704.

[0109] In step S702, the primary controller sends a redundant heartbeat request signal to the standby controller at intervals of a first time period.

[0110] In step S704, after receiving the redundant heartbeat request signal, the standby controller returns a redundant heartbeat response signal to the active controller within a first time period, so as to establish a heartbeat link with the active controller.

[0111] So far, a control method for controlling a system according to some embodiments of the present disclosure is provided, which implements a heartbeat link between a main controller and a standby controller.

[0112] In some embodiments, the plurality of expansion modules include a first expansion module. The method may further include: the first expansion module broadcasts an address broadcast frame including its own address to the expansion bus after a random time; if no redundant host response frame is received from an expansion module with the same address within a predetermined time, or an address broadcast frame is received from an expansion module with the same address within a predetermined time, the first expansion module itself is determined to be a primary expansion module; and if a redundant host response frame is received within a predetermined time, the first expansion module itself is determined to be a standby expansion module, wherein the predetermined time is greater than the random time. This embodiment implements the expansion module's determination of its own mode (primary expansion module mode or standby expansion module mode).

[0113] Figure 8 is a flow chart showing a control method for controlling a system according to other embodiments of the present disclosure. Figure 8 Describe in detail the process by which the expansion module determines its own mode (main expansion module mode or standby expansion module mode). Figure 8 As shown, the method includes steps S802 to S812.

[0114] In step S802, the expansion module broadcasts an address broadcast frame including its own address to the expansion bus after a random delay time.

[0115] In step S804, the extension module determines whether a response frame is received within a predetermined time. If yes, the process proceeds to step S806, otherwise the process proceeds to step S808.

[0116] In step S806, the expansion module determines which expansion module it is based on the frame type. If it is a broadcast address frame, the process proceeds to step S808; if it is a redundant host frame, the process proceeds to step S810.

[0117] In step S808, the expansion module determines itself as the main expansion module;

[0118] In step S810, the extension module determines itself as a standby extension module.

[0119] In step S812, the expansion module sends a redundant host frame.

[0120] So far, the process of determining the mode of the expansion module is provided. Based on the redundant active-standby competition mechanism of the expansion module communication address and online time, the active-standby status of the expansion module can be quickly confirmed.

[0121] In some embodiments, the control method may further include: the main controller publishes the data from the field protocol device to the proxy server module in the main controller; and the standby controller receives the subscription message sent by the proxy server module to obtain the data of the field protocol device, wherein the subscription message contains the data of the field protocol device.

[0122] In some embodiments, the control method may also include: the main controller sends a data read request to the field protocol device; the field protocol device outputs response data in the form of a differential voltage to the expansion bus after receiving the data read request; and the main controller and the standby controller detect changes in the expansion bus voltage to obtain response data.

[0123] In some embodiments, the control method may also include: the main controller sends an extended heartbeat request signal to multiple expansion modules; and after receiving the extended heartbeat request signal from the expansion bus, at least one expansion module among the multiple expansion modules returns an extended heartbeat response signal to the main controller to establish a heartbeat link with the main controller.

[0124] In some embodiments, the control method may also include: if the standby controller does not receive a redundant heartbeat request signal and an extended heartbeat request signal from the main controller within a first time period, it determines that the main controller has failed, autonomously switches to the main controller mode, lifts communication restrictions, initiates read and write control to the on-site protocol device, and reports the information that it has switched to the main controller mode to the monitoring server.

[0125] In some embodiments, the control method may further include: if the main controller does not receive the redundant heartbeat response signal and the extended heartbeat response signal of the standby controller within the first time period, determining that the standby controller fails, and reporting the failure information of the standby controller to the monitoring server.

[0126] In some embodiments, the control method may further include: the main controller sends an expansion heartbeat request signal to multiple expansion modules, and if the expansion heartbeat response signal of the main expansion module is not received within a second time period, it is determined that the main expansion module has a fault, and the information that the main expansion module has a fault is reported to the monitoring server; and if the standby expansion module with the same address as the main expansion module does not receive the expansion heartbeat response signal of the main expansion module within the second time period, it is determined that the main expansion module has a fault and autonomously switches to the main expansion module.

[0127] In some embodiments, the control method may also include: after the main controller is powered on, the main controller sends the local file of the main controller to the standby controller; and the standby controller compares the local file of the standby controller with the local file of the main controller, and when the local file of the standby controller is inconsistent with the local file of the main controller, synchronizing the local file of the main controller to the standby controller.

[0128] The control system and method of the disclosed embodiments can realize interference-free hot switching of the controller when a building control system fails, and the host abnormality judgment adopts double verification of redundant communication interface data and expansion bus data to avoid the problem of dual hosts in the system due to the abnormality of a single data synchronization line, which causes major accidents such as system downtime. The use of a redundant communication interface and an expansion bus dual data synchronization mechanism can greatly reduce the communication bandwidth pressure of the data synchronization interface and improve the reliability of the control system.

[0129] Fig. 9 Schematically shows a block diagram of a control system according to some other embodiments of the present disclosure. The control system includes a memory 910 and a processor 920. Among them:

[0130] The memory 910 can be a disk, a flash memory, or any other non-volatile storage medium. The memory is used to store Figure 7 and / or Figure 8 The instructions in the corresponding embodiment, or the instructions corresponding to other method embodiments.

[0131] The processor 920 is coupled to the memory 910 and can be implemented as one or more integrated circuits, such as a microprocessor or a microcontroller. The processor 920 is used to execute instructions stored in the memory, thereby preventing the occurrence of system data anomalies as much as possible.

[0132] It should be noted that the control system may include multiple memories 910 and multiple processors 920, and the multiple memories 910 and the multiple processors 920 may be matched and located in different controllers or different expansion modules.

[0133] In some embodiments, it is also possible to Fig.10 As shown, the control system 1000 includes a memory 1010 and a processor 1020. The processor 1020 is coupled to the memory 1010 via a BUS 1030. The control system 1000 can also be connected to an external storage device 1050 via a storage interface 1040 to call external data, and can also be connected to a network or another computer system (not shown) via a network interface 1060, which will not be described in detail here.

[0134] In this embodiment, data instructions are stored in a memory, and then processed by a processor, thereby preventing system data anomalies from occurring as much as possible.

[0135] It should be noted that the control system may include multiple memories 1010, multiple processors 1020, multiple BUS buses 1030, multiple storage interfaces 1040, multiple external storage devices 1050, and multiple network interfaces 1060. The multiple memories 1010, multiple processors 1020, multiple BUS buses 1030, multiple storage interfaces 1040, multiple external storage devices 1050, and multiple network interfaces 1060 may be matched and located in different controllers or different expansion modules.

[0136] In another embodiment, the present disclosure further provides a computer-readable storage medium having computer program instructions stored thereon, which when executed by a processor implements Figure 7 and / or Figure 8 The steps of the method in the corresponding embodiment, or the steps corresponding to other method embodiments. Those skilled in the art should understand that the embodiments of the present disclosure can be provided as methods, devices, or computer program products. Therefore, the present disclosure can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present disclosure can take the form of a computer program product implemented on one or more computer-usable non-transient storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0137] The present disclosure is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present disclosure. It should be understood that each process and / or block in the flowchart and / or block diagram and the combination of processes and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0138] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0139] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0140] So far, the present disclosure has been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0141] Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A control system, include: Main controller, standby controller and multiple expansion modules, The multiple expansion modules include at least one main expansion module and corresponding at least one standby expansion module, the multiple expansion modules are connected to the main controller and the standby controller via an expansion bus, and each expansion module is connected to the field protocol device via a device connection line; The main controller is used to perform data reading and writing operations on the field protocol device through the expansion bus and the main expansion module; The standby controller is used to receive data from the expansion bus and not send control data to the expansion bus; The main expansion module is used to receive data from the expansion bus and send data to the expansion bus; The standby expansion module is used to receive data from the expansion bus and not send data to the expansion bus; Wherein, the main expansion module and the corresponding standby expansion module have the same address, and the main expansion module and the standby expansion module having the same address are linked to the same field protocol device; The multiple expansion modules include a first expansion module, and the first expansion module is used to broadcast an address broadcast frame including its own address to the expansion bus after a random time has passed. If no redundant host response frame is received from the expansion module with the same address within a predetermined time, or an address broadcast frame is received from the expansion module with the same address within the predetermined time, the first expansion module itself is determined to be a main expansion module; if the redundant host response frame is received within the predetermined time, the first expansion module itself is determined to be a standby expansion module, wherein the predetermined time is greater than the random time.

2. The control system according to claim 1, in, The main controller is also used to send a redundant heartbeat request signal to the standby controller at intervals of a first time period; The standby controller is further configured to return a redundant heartbeat response signal to the main controller within the first time period after receiving the redundant heartbeat request signal, so as to establish a heartbeat link with the main controller.

3. The control system according to claim 1, in, The main controller is used to publish the data from the field protocol device to the proxy server module in the main controller; The standby controller is used to receive a subscription message sent by the proxy server module to obtain the data of the field protocol device, wherein the subscription message includes the data of the field protocol device.

4. The control system according to claim 1, in, The main controller is used to send a data reading request to the field protocol device; The field protocol device is used to output response data in the form of differential voltage to the expansion bus after receiving the data read request; The main controller and the standby controller detect changes in the extended bus voltage to obtain the response data.

5. The control system according to claim 2, in, The main controller is used to send an expansion heartbeat request signal to the multiple expansion modules; At least one expansion module among the plurality of expansion modules is used for returning an expansion heartbeat response signal to the main controller after receiving the expansion heartbeat request signal from the expansion bus, so as to establish a heartbeat link with the main controller.

6. The control system according to claim 5, further comprising: include: The monitoring server is respectively connected to the main controller and the standby controller for communication, and is used to obtain fault information of the main controller, the standby controller or the main expansion module.

7. The control system according to claim 6, in, If the standby controller does not receive a redundant heartbeat request signal and an extended heartbeat request signal from the main controller within the first time period, it determines that the main controller has failed, autonomously switches to the main controller mode, removes communication restrictions, initiates read and write control to the on-site protocol device, and reports the information that it has switched to the main controller mode to the monitoring server.

8. The control system according to claim 6, in, The main controller is also used to determine that the standby controller fails if no redundant heartbeat response signal and extended heartbeat response signal of the standby controller are received within the first time period, and report the failure information of the standby controller to the monitoring server.

9. The control system according to claim 6, in, The main controller is used to send an expansion heartbeat request signal to the multiple expansion modules, and if no expansion heartbeat response signal is received from the main expansion module within a second time period, it is determined that the main expansion module fails, and the information that the main expansion module fails is reported to the monitoring server; The standby expansion module with the same address as the main expansion module is also used to determine that the main expansion module fails if no expansion heartbeat response signal is received from the main expansion module within the second time period, and autonomously switch to the main expansion module.

10. The control system according to claim 1, in, The main controller is also used to send the local file of the main controller to the standby controller after power-on; The standby controller is also used to compare the local file of the standby controller with the local file of the main controller, and when the local file of the standby controller is inconsistent with the local file of the main controller, synchronize the local file of the main controller to the standby controller.

11. The control system according to claim 1, in, The main controller and the standby controller are respectively provided with a first indicator light panel, and the first indicator light panel includes: The first operation mode indicator light is used to indicate that the current controller is in a redundant operation mode; A first data sending indicator light, used to indicate that the current controller sends data through a device bus, wherein the main controller and the standby controller are connected to a switch through the device bus, and the switch is communicatively connected to the field protocol device; A first data receiving indicator light, used to indicate that the current controller receives data through the device bus; A second data sending indicator light, used to indicate that the current controller sends data via the expansion bus; A second data reception indicator light, which is used to indicate that the current controller receives data through the expansion bus; and A first heartbeat link indicator light, which is used to indicate that the current controller implements a heartbeat link.

12. The control system according to claim 1,[[]]END]] wherein,[[]]END]] Each expansion module is provided with a second indicator light panel, and the second indicator light panel includes:[[]]END]] A second operation mode indicator light, which is used to indicate that the current expansion module is in a redundant operation mode; A third data transmission indicator light, which is used to indicate that the current expansion module transmits data; A third data reception indicator light, which is used to indicate that the current expansion module receives data; and A second heartbeat link indicator light, which is used to indicate that the current expansion module implements a heartbeat link.

13. A control method for the control system according to any one of claims 1 to 12,[[]]END]] including:[[]]END]] The main controller sends a redundant heartbeat request signal to the standby controller every first time period; and After receiving the redundant heartbeat request signal, the standby controller returns a redundant heartbeat response signal to the main controller within the first time period, so as to establish a heartbeat link with the main controller.

14. The control method according to claim 13,[[]]END]] wherein,[[]]END]] The multiple expansion modules include a first expansion module; The control method further includes:[[]]END]] The first expansion module broadcasts an address broadcast frame containing its own address to the expansion bus after a random time; If a redundant host response frame from an expansion module with the same address is not received within a predetermined time, or an address broadcast frame from an expansion module with the same address is received within the predetermined time, it is determined that the first expansion module itself is the main expansion module; and If the redundant host response frame is received within the predetermined time, it is determined that the first expansion module itself is the standby expansion module, where the predetermined time is greater than the random time.

15. The control method according to claim 13, further including:[[]]END]] The main controller publishes the data from the field protocol device to the proxy server module in the main controller; and The standby controller receives the subscription message sent by the proxy server module to obtain the data of the field protocol device, where the subscription message contains the data of the field protocol device.

16. The control method according to claim 13, further including:[[]]END]] The main controller sends a data reading request to the field protocol device; After receiving the data reading request, the field protocol device outputs response data in the form of differential voltage to the expansion bus; and The main controller and the standby controller detect the change in the expansion bus voltage to obtain the response data.

17. The control method according to claim 13, further including:[[]]END]] The main controller sends an expansion heartbeat request signal to the multiple expansion modules; and At least one expansion module among the multiple expansion modules returns an expansion heartbeat response signal to the main controller after receiving the expansion heartbeat request signal from the expansion bus, so as to establish a heartbeat link with the main controller.

18. The control method according to claim 13, further including:[[]]END]] If the standby controller does not receive the redundant heartbeat request signal and the extended heartbeat request signal from the main controller within the first time period, it determines that the main controller has failed, autonomously switches to the main controller mode, removes communication restrictions, initiates read and write control to the on-site protocol device, and reports the information that it has switched to the main controller mode to the monitoring server.

19. The control method according to claim 13, further comprising: include: If the main controller does not receive the redundant heartbeat response signal and the extended heartbeat response signal of the standby controller within the first time period, it determines that the standby controller fails, and reports the failure information of the standby controller to the monitoring server.

20. The control method according to claim 13, further comprising: include: The main controller sends an expansion heartbeat request signal to the plurality of expansion modules, and if no expansion heartbeat response signal is received from the main expansion module within a second time period, determines that the main expansion module fails, and reports information that the main expansion module fails to the monitoring server; and If the standby expansion module with the same address as the main expansion module does not receive the expansion heartbeat response signal of the main expansion module within the second time period, it determines that the main expansion module fails and autonomously switches to the main expansion module.

21. The control method according to claim 13, further comprising: include: After the main controller is powered on, the main controller sends the local file of the main controller to the standby controller; and The standby controller compares the local file of the standby controller with the local file of the main controller, and synchronizes the local file of the main controller to the standby controller if the local file of the standby controller is inconsistent with the local file of the main controller.

22. A control system, include: Memory; as well as A processor coupled to the memory, the processor being configured to execute the method according to any one of claims 13 to 21 based on instructions stored in the memory.

23. A computer-readable storage medium having computer program instructions stored thereon, wherein the computer program instructions, when executed by a processor, implement the method according to any one of claims 13 to 21.

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