Signal transmission system and method

Abstract

The embodiment of the invention provides a signal transmission system and method, and relates to the technical field of communication. A first instrument control system of the signal transmission system converts a completed step serial number into a binary numerical value to obtain a switching value signal, and transmits the switching value signal to a second instrument control system, so that the second instrument control system determines the completed step serial number by analyzing the switching value signal. Therefore, the number of signals needing to be transmitted is greatly reduced, and the signal transmission process is simplified. Furthermore, due to the reduction of the number of the transmission signals, not only are the requirements on the acquisition module and the output module reduced, but also valuable space resources are released, such as key resources such as electronic room space and bridge capacity can be distributed and utilized more reasonably, and the operation efficiency and the management level of the whole facility can be improved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a signal transmission system and method. Background Art

[0002] With the increasing scale of nuclear power plant systems, the increasing complexity of operating conditions and the increasing number of equipment, the Automatic Power Plant Startup and Shutdown System (APS) came into being in order to reduce the manual operation pressure of operators during unit startup and shutdown and improve the degree of automation of nuclear power plants.

[0003] In the related technology, the APS system realizes automation during the startup and shutdown of the unit through a series of pre-set sequence control programs. In addition, in order to comply with strict nuclear safety standards, a hierarchical control strategy is adopted in the design of the APS system. Among them, the safety-level instrumentation and control system is responsible for executing those key operation logics that directly affect nuclear safety, while the non-safety-level instrumentation and control system is responsible for executing those judgment logics, such as deciding when to start or end a certain step.

[0004] However, since the APS system contains a large number of sequential control programs, each of which consists of multiple steps, if each step requires the non-safety-level instrumentation and control system to feedback the step judgment result to the safety-level instrumentation and control system, the non-safety-level instrumentation and control system needs to transmit a large number of signals to the safety-level instrumentation and control system. In order to support the transmission of so many signals, not only does it need to increase the number of acquisition modules and output modules to perform signal acquisition and transmission, but it also places high demands on the electronic space, bridge capacity and cable cost of the nuclear power plant. Summary of the invention

[0005] Based on the above problems, the present application provides a signal transmission system and method, which can reduce the number of signals that need to be transmitted and simplify the signal transmission process. Furthermore, due to the reduction in the number of transmitted signals, not only the demand for acquisition modules and output modules is reduced, but also valuable space resources are released. For example, key resources such as electronic space and bridge capacity can be more reasonably allocated and utilized, which helps to improve the overall operation efficiency and management level of the facility.

[0006] The embodiments of the present application disclose the following technical solutions:

[0007] In a first aspect, the present application discloses a signal transmission system, the system comprising: a first instrumentation and control system and a second instrumentation and control system;

[0008] The first instrumentation and control system is used to obtain a switch signal by converting the completed step number into a binary value; and transmit the switch signal to the second instrumentation and control system;

[0009] The second instrumentation and control system is used to determine the completed step number by analyzing the switch signal.

[0010] Optionally, the first instrumentation and control system is specifically used for: if the completed step number is a single digit, obtaining a switch signal by converting the single digit value of the completed step number into a binary value.

[0011] Optionally, the first instrumentation and control system is specifically used for: if the completed step number is a ten-digit number, converting the ones digit value and the tens digit value of the completed step number into binary values ​​respectively; and determining the switch signal by splicing the binary value corresponding to the ones digit value and the binary value corresponding to the tens digit value.

[0012] Optionally, the first instrumentation and control system and the second instrumentation and control system are connected via hard wiring, and the first instrumentation and control system is specifically used to: transmit the switch signal to the second instrumentation and control system via the hard wiring.

[0013] Optionally, the first instrumentation and control system is specifically configured to: generate a signal check code according to the switch quantity signal; and transmit the switch quantity signal after the check code is attached to the switch quantity signal to the second instrumentation and control system;

[0014] The second instrumentation and control system is specifically used for: if it is determined by analyzing the attached switch signal that the signal check code matches the switch signal, then determining the completed step number by analyzing the switch signal.

[0015] In a second aspect, the present application provides a signal transmission method, which is applied to a first instrumentation and control system, and the method includes:

[0016] By converting the completed step number into a binary value, a switch signal is obtained;

[0017] The switch signal is transmitted to a second instrumentation and control system, so that the second instrumentation and control system determines the completed step number by analyzing the switch signal.

[0018] Optionally, the step of converting the completed step number into a binary value to obtain a switch signal includes:

[0019] If the completed step number is a single-digit number, a switch signal is obtained by converting the single-digit value of the completed step number into a binary value.

[0020] Optionally, the step of converting the completed step number into a binary value to obtain a switch signal includes:

[0021] If the completed step number is a ten-digit number, convert the ones-digit value and the tens-digit value of the completed step number into binary values ​​respectively;

[0022] The switch value signal is determined by concatenating the binary value corresponding to the ones-digit value and the binary value corresponding to the tens-digit value.

[0023] Optionally, the first instrumentation and control system and the second instrumentation and control system are connected via hard wiring; and the step of transmitting the switch signal to the second instrumentation and control system comprises:

[0024] The switch signal is transmitted to the second instrumentation and control system through the hard wiring.

[0025] In a third aspect, the present application provides a signal transmission method, which is applied to a second instrumentation and control system, and the method includes:

[0026] Receiving a switch signal transmitted by the first instrumentation and control system;

[0027] The completed step number is determined by analyzing the switch signal.

[0028] Compared with the prior art, this application has the following beneficial effects:

[0029] The embodiment of the present application provides a signal transmission system and method, in which the first instrumentation and control system of the signal transmission system converts the completed step number into a binary value to obtain a switch signal, and transmits the switch signal to the second instrumentation and control system, so that the second instrumentation and control system determines the completed step number by analyzing the switch signal. This greatly reduces the number of signals that need to be transmitted and simplifies the signal transmission process. Furthermore, due to the reduction in the number of transmitted signals, not only the demand for acquisition modules and output modules is also reduced, but also valuable space resources are released. For example, key resources such as electronic space and bridge capacity can be more reasonably allocated and utilized, which helps to improve the overall operational efficiency and management level of the facility. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0031] Figure 1 is a schematic diagram of an APS system;

[0032] Figure 2 A schematic diagram of a signal transmission system provided in an embodiment of the present application;

[0033] Figure 3 A flow chart of a signal transmission method provided in an embodiment of the present application;

[0034] Figure 4 A flowchart of another signal transmission method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] First, the technical terms involved in this application are explained:

[0036] The Automatic Power Plant Startup and Shutdown System (APS) is an automated control system for power plants that is designed to automatically start and stop the generator sets in the power plant. This system can significantly reduce the need for manual operation, improve efficiency, and shorten startup time and reduce fuel consumption while ensuring safety.

[0037] As described above, in order to comply with strict nuclear safety standards, a hierarchical control strategy is adopted in the design of the APS system. Figure 1 , which is a schematic diagram of an APS system. The APS system includes a safety-level instrumentation and control system and a non-safety-level instrumentation and control system. Among them, the safety-level instrumentation and control system is responsible for executing those key operation logics that directly affect nuclear safety, while the non-safety-level instrumentation and control system is responsible for executing those judgment logics, such as deciding when to start or end a certain step.

[0038] However, since the APS system contains a large number of sequential control programs, each of which consists of multiple steps, if each step requires the non-safety-level instrumentation and control system to feedback the step judgment result to the safety-level instrumentation and control system, the non-safety-level instrumentation and control system needs to transmit a large number of signals to the safety-level instrumentation and control system. In order to support the transmission of so many signals, not only does it need to increase the number of acquisition modules and output modules to perform signal acquisition and transmission, but it also places high demands on the electronic space, bridge capacity and cable cost of the nuclear power plant.

[0039] Furthermore, since the signal transmission path from the non-safety-level instrumentation and control system to the safety-level instrumentation and control system is long, there may be a situation where the signal has not been reset but has entered the next step, resulting in a fault in the step sequence signal. If the step sequence signal fails, the sequential control program may not be able to continue to execute, thus affecting the normal operation of the unit.

[0040] After research, the inventor proposed a signal transmission system and method, in which the first instrumentation and control system of the signal transmission system converts the completed step number into a binary value to obtain a switch signal, and transmits the switch signal to the second instrumentation and control system, so that the second instrumentation and control system determines the completed step number by analyzing the switch signal. This greatly reduces the number of signals that need to be transmitted and simplifies the signal transmission process. Furthermore, due to the reduction in the number of transmitted signals, not only the demand for acquisition modules and output modules is also reduced, but also valuable space resources are released. For example, key resources such as electronic space and bridge capacity can be more reasonably allocated and utilized, which helps to improve the overall operation efficiency and management level of the facility.

[0041] Furthermore, by hard-wiring the first instrumentation and control system and the second instrumentation and control system, the direct physical connection enhances the stability and reliability of signal transmission, reduces the problem of step signal failure (including signal loss and delay problems, etc.) that may be caused by wireless transmission or other forms of connection, and reduces the probability of the sequential control program being unable to continue to execute and affecting the normal operation of the unit.

[0042] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] See also Figure 2 , which is a schematic diagram of a signal transmission system provided in an embodiment of the present application. The signal transmission system 20 includes: a non-safety-level instrumentation and control system 21 (ie, a first instrumentation and control system) and a safety-level instrumentation and control system 22 (ie, a second instrumentation and control system).

[0044] Among them, the non-safety-level instrumentation and control system 21 is responsible for generating the judgment logic in the sequential control program and converting the completed step sequence number into a switch signal in a specific format.

[0045] The safety-level instrumentation and control system 22 is responsible for receiving the switch quantity signal from the non-safety-level instrumentation and control system 21 and executing corresponding operation steps accordingly.

[0046] S201: The non-safety-level instrumentation and control system obtains a switch signal by converting the completed step number into a binary value.

[0047] In a specific implementation, if the completed step number is a single digit, the single digit value of the completed step number is converted into a binary value to obtain a switch signal. Specifically, when the step number is any one of 1-9, 4 switch signals can be used to represent it. Exemplarily, if the step number is 3, it can be converted into a switch signal of 0011 (binary). In another specific implementation, if the completed step number is a tens digit, the single digit value and the tens digit value of the completed step number are converted into binary values ​​respectively; the switch signal is determined by splicing the binary value corresponding to the single digit value and the binary value corresponding to the tens digit value. Specifically, when the step number is any one of 10-99, 8 4 switch signals can be used to represent it. Exemplarily, if the step number is 57, it can be converted into a switch signal of 01010111.

[0048] It should be noted that the above binary encoding method has good flexibility, and the number of binary bits can be adjusted according to the actual application scenario to adapt to different step number ranges. If it is necessary to support larger step numbers in the future, the signal transmission system 20 can be easily expanded and upgraded by increasing the number of binary bits without changing the basic encoding logic.

[0049] It is understandable that, compared to the method that requires independent feedback signals for each step, this encoding method based on step numbers greatly reduces the total number of switch signals required. For example, when processing a large number of sequential control programs, if each step transmits a signal separately, then for a program containing 100 steps, 100 signal lines may be required. After adopting step number encoding, only a few signal lines are needed to represent all steps. Due to the reduction in the number of signals, not only the demand for corresponding acquisition modules, output modules and related cables is also reduced, thereby reducing the hardware cost of the signal transmission system 20, but also the requirements for electronic space are reduced, while reducing the pressure on bridge capacity, which is particularly important for facilities with limited space. Further, by reducing the number of signal lines, the possibility of signal delays or errors caused by long-distance transmission can also be reduced, and fewer signal lines mean fewer connection points, further reducing potential failure points, thereby improving the reliability and stability of the entire signal transmission system 20.

[0050] S202: The non-safety-level instrumentation and control system transmits the switch quantity signal to the safety-level instrumentation and control system.

[0051] In some specific implementations, the non-safety-level instrumentation and control system 21 and the safety-level instrumentation and control system 22 can be connected by hard wiring. Then, the non-safety-level instrumentation and control system 21 transmits the switch signal to the safety-level instrumentation and control system 22 through hard wiring. Among them, hard wiring refers to a communication method that directly connects the non-safety-level instrumentation and control system 21 and the safety-level instrumentation and control system 22 using a physical cable. This method does not rely on network protocols or other software layer communication mechanisms, but transmits information through level changes.

[0052] It is understandable that the advantages of using hard wiring for the transmission of switch signals are: first, hard wiring has high reliability and anti-interference ability, and is suitable for environments with extremely high safety requirements such as nuclear power plants. Second, since complex network protocol processing is not required, the signal reaches the destination with very low latency and almost instantaneously, ensuring real-time response. Third, if there is a problem with signal transmission, engineers can quickly locate and solve the fault point by checking the specific cable line, which is convenient for maintenance and repair.

[0053] S203: The safety-level instrumentation and control system determines the completed step number by analyzing the switch signal.

[0054] The safety-level instrumentation and control system 22 receives switch signals from the non-safety-level instrumentation and control system 21 through hard wiring. These switch signals are represented in the form of binary values, where each bit represents a switch state (0 or 1). When the switch signals arrive, the safety-level instrumentation and control system 21 first needs to parse these switch signals.

[0055] Specifically, if a 4-bit binary number is obtained by parsing the switch signal, it corresponds to the step number of the unit digit (1 to 9). For example, if 0011 is obtained by parsing the switch signal, the step number can be determined to be 3. If an 8-bit binary number is obtained by parsing the switch signal, it corresponds to the step number of the ten digit (10 to 99), and the first 4 digits represent the ten digit and the last 4 digits represent the unit digit. For example, if 01010111 is obtained by parsing the switch signal, it can be split into 0101 (tens digit 5) and 0111 (unit digit 7), thereby determining the step number to be 57.

[0056] Once the completed step number is determined, the safety-level instrumentation and control system 22 can execute the corresponding control logic or update the system status according to the completed step number.

[0057] It is understandable that, due to the use of clear binary coding rules, the safety-level instrumentation and control system 22 can directly and accurately parse the completed step numbers, reducing the possibility of errors and ensuring the stability and reliability of the signal transmission system 20.

[0058] In order to further improve the accuracy of data transmission, signal check codes are introduced in some specific implementations:

[0059] Specifically, first, before sending the switch signal, the non-safety-level instrumentation and control system 21 generates a signal check code according to the switch signal, then attaches the signal check code to the switch signal, and transmits the attached switch signal to the safety-level instrumentation and control system 22.

[0060] Subsequently, after receiving the attached switch signal, the safety-level instrumentation and control system 22 will first parse the attached switch signal to check whether the signal check code matches the switch signal.

[0061] If the signal check code matches the switch signal, it means that the switch signal has not changed during the transmission process and is complete. At this time, the safety-level instrumentation and control system 22 will continue to parse the switch signal to determine the completed step number.

[0062] If the signal check code does not match the switch signal, it means that the switch signal may be interfered or damaged during the transmission process due to electromagnetic interference, line noise, hardware failure, etc. At this time, the safety-level instrumentation and control system 22 may send a retransmission request to the non-safety-level instrumentation and control system 21 based on the automatic retransmission request (ARQ, Automatic Repeat reQuest) mechanism, requiring the non-safety-level instrumentation and control system 21 to resend the original switch signal. At the same time, regardless of whether the problem can be solved immediately, the safety-level instrumentation and control system 22 should trigger an alarm and record the event in detail in the log file for subsequent analysis and maintenance personnel to check.

[0063] In summary, the embodiment of the present application discloses a signal transmission system, in which the first instrumentation and control system of the signal transmission system converts the completed step number into a binary value to obtain a switch signal, and transmits the switch signal to the second instrumentation and control system, so that the second instrumentation and control system determines the completed step number by parsing the switch signal. This greatly reduces the number of signals that need to be transmitted and simplifies the signal transmission process. Furthermore, due to the reduction in the number of transmitted signals, not only the demand for acquisition modules and output modules is reduced, but also valuable space resources are released, such as key resources such as electronic space and bridge capacity can be more reasonably allocated and utilized, which helps to improve the overall operation efficiency and management level of the facility. Furthermore, by connecting the first instrumentation and control system and the second instrumentation and control system through hard wiring, the direct physical connection method enhances the stability and reliability of signal transmission, reduces the problem of step signal failure that may occur due to wireless transmission or other forms of connection (including signal loss and delay problems, etc.), and reduces the probability that the sequential control program cannot continue to execute and affects the normal operation of the unit.

[0064] See also Figure 3 , which is a flow chart of a signal transmission method provided in an embodiment of the present application. The signal transmission method is applied to a non-safety-level instrumentation and control system 21 (i.e., the first instrumentation and control system), and the method includes:

[0065] S301: Obtain a switch signal by converting the completed step number into a binary value.

[0066] In some specific implementations, a switch signal is obtained by converting the completed step number into a binary value, including: if the completed step number is a single digit, then a switch signal is obtained by converting the single digit value of the completed step number into a binary value.

[0067] In some specific implementations, a switch signal is obtained by converting the completed step number into a binary value, including: if the completed step number is a ten-digit number, converting the ones digit and the tens digit of the completed step number into binary values ​​respectively; and determining the switch signal by concatenating the binary value corresponding to the ones digit and the binary value corresponding to the tens digit.

[0068] S302: Transmitting the switch signal to the second instrumentation and control system, so that the second instrumentation and control system determines the completed step number by analyzing the switch signal.

[0069] In some specific implementations, the first instrumentation and control system and the second instrumentation and control system are connected via hard wiring; transmitting the switch signal to the second instrumentation and control system includes: transmitting the switch signal to the second instrumentation and control system via hard wiring.

[0070] In summary, the embodiment of the present application discloses a signal transmission method, in which the first instrumentation and control method of the signal transmission method converts the completed step number into a binary value to obtain a switch signal, and transmits the switch signal to the second instrumentation and control method, so that the second instrumentation and control method determines the completed step number by parsing the switch signal. This greatly reduces the number of signals that need to be transmitted and simplifies the signal transmission process. Furthermore, due to the reduction in the number of transmitted signals, not only the demand for acquisition modules and output modules is reduced, but also valuable space resources are released, such as key resources such as electronic space and bridge capacity can be more reasonably allocated and utilized, which helps to improve the overall facility operation efficiency and management level. Further, by connecting the first instrumentation and control system and the second instrumentation and control system through hard wiring, the direct physical connection method enhances the stability and reliability of signal transmission, reduces the problem of step signal failure that may occur due to wireless transmission or other forms of connection (including signal loss and delay problems, etc.), and reduces the probability that the sequential control program cannot continue to execute and affects the normal operation of the unit.

[0071] See also Figure 4, which is a flow chart of another signal transmission method provided in an embodiment of the present application. The signal transmission method is applied to the safety-level instrumentation and control system 22 (i.e., the second instrumentation and control system), and the method includes:

[0072] S401: Receive a switch signal transmitted by a first instrumentation and control system.

[0073] S402: Determine the completed step number by analyzing the switch signal.

[0074] In summary, the embodiment of the present application discloses a signal transmission method, in which the first instrumentation and control method of the signal transmission method converts the completed step number into a binary value to obtain a switch signal, and transmits the switch signal to the second instrumentation and control method, so that the second instrumentation and control method determines the completed step number by parsing the switch signal. This greatly reduces the number of signals that need to be transmitted and simplifies the signal transmission process. Furthermore, due to the reduction in the number of transmitted signals, not only the demand for acquisition modules and output modules is reduced, but also valuable space resources are released, such as key resources such as electronic space and bridge capacity can be more reasonably allocated and utilized, which helps to improve the overall facility operation efficiency and management level. Further, by connecting the first instrumentation and control system and the second instrumentation and control system through hard wiring, the direct physical connection method enhances the stability and reliability of signal transmission, reduces the problem of step signal failure that may occur due to wireless transmission or other forms of connection (including signal loss and delay problems, etc.), and reduces the probability that the sequential control program cannot continue to execute and affects the normal operation of the unit.

[0075] The "first" and "second" in the names such as "first" and "second" (if any) mentioned in the embodiments of the present application are only used as name identifiers and do not represent the first or second in order.

[0076] Through the description of the above implementation methods, it can be known that those skilled in the art can clearly understand that all or part of the steps in the above-mentioned embodiment method can be implemented by means of software plus a general hardware platform. Based on such an understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a storage medium, such as a read-only memory (ROM) / RAM, a magnetic disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network communication device such as a router) to execute the methods described in each embodiment of the present application or some parts of the embodiments.

[0077] It should be noted that each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments. The device and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components indicated as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0078] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A signal transmission system, characterized in that: The system comprises: a first instrumentation and control system and a second instrumentation and control system; The first instrumentation and control system is used to obtain a switch signal by converting the completed step number into a binary value; and transmit the switch signal to the second instrumentation and control system; The second instrumentation and control system is used to determine the completed step number by analyzing the switch signal.

2. The system according to claim 1, characterized in that The first instrumentation and control system is specifically used for: if the completed step number is a single digit, obtaining a switch signal by converting the single digit value of the completed step number into a binary value.

3. The system according to claim 1, characterized in that The first instrumentation and control system is specifically used for: if the completed step number is a ten-digit number, converting the ones digit value and the tens digit value of the completed step number into binary values ​​respectively; and determining the switch signal by splicing the binary value corresponding to the ones digit value and the binary value corresponding to the tens digit value.

4. The system according to claim 1, characterized in that The first instrumentation and control system and the second instrumentation and control system are connected via hard wiring, and the first instrumentation and control system is specifically used to transmit the switch signal to the second instrumentation and control system via the hard wiring.

5. The system according to claim 1, characterized in that The first instrumentation and control system is specifically used to: generate a signal check code according to the switch quantity signal; and transmit the switch quantity signal after the check code is attached to the switch quantity signal to the second instrumentation and control system; The second instrumentation and control system is specifically used for: if it is determined by analyzing the attached switch signal that the signal check code matches the switch signal, then determining the completed step number by analyzing the switch signal.

6. A signal transmission method, characterized in that: Applied to the first instrumentation and control system, the method comprises: By converting the completed step number into a binary value, a switch signal is obtained; The switch signal is transmitted to a second instrumentation and control system, so that the second instrumentation and control system determines the completed step number by analyzing the switch signal.

7. The method according to claim 6, characterized in that The method of converting the completed step number into a binary value to obtain a switch signal includes: If the completed step number is a single-digit number, a switch signal is obtained by converting the single-digit value of the completed step number into a binary value.

8. The method according to claim 6, characterized in that The method of converting the completed step number into a binary value to obtain a switch signal includes: If the completed step number is a ten-digit number, convert the ones-digit value and the tens-digit value of the completed step number into binary values ​​respectively; The switch value signal is determined by concatenating the binary value corresponding to the ones-digit value and the binary value corresponding to the tens-digit value.

9. The method according to claim 6, characterized in that The first instrumentation and control system and the second instrumentation and control system are connected by hard wiring; the transmitting the switch signal to the second instrumentation and control system comprises: The switch signal is transmitted to the second instrumentation and control system through the hard wiring.

10. A signal transmission method, characterized in that: Applied to the second instrumentation and control system, the method comprises: Receiving a switch signal transmitted by the first instrumentation and control system; By analyzing the switch signal, the completed step number is determined.

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