An automated testing method, storage medium, and electronic device

Abstract

This application provides an automatic testing method, storage medium, and electronic device, relating to the field of electricity meter testing technology. The method includes: acquiring a specified number of freezes; determining whether the number of freezes is less than a specified number; if the number of freezes is less than the specified number, setting the electricity meter time, and storing frozen data when the electricity meter time reaches the freeze time, repeatedly executing the steps from determining whether the number of freezes is less than the specified number to storing frozen data until the number of freezes reaches the specified number; if the number of freezes reaches the specified number, performing electricity meter data reading according to a specified reading range. By setting the electricity meter time, frozen data can be obtained quickly, improving testing efficiency. Software-based reading enables automatic testing and automatic data reading, saving significant labor costs.

Description

Technical Field

[0001] This application relates to the field of electricity meter testing technology, and in particular to automatic testing methods. Background Technology

[0002] Existing electricity meters generate data according to the meter's time when measuring load-related parameters. For example, the electricity meter records a specific year, month, day, hour, minute, and second. Data can be generated at the 0th second of every minute, and then frozen (stored). The load data can form a function curve that varies with time, called the load curve.

[0003] The function of freezing and storing data that constitutes the load curve has been widely adopted in State Grid 20 standard meters and smart IoT energy meters. As market demands for storage space and operational stability of energy meters increase, and the requirements for the freeze storage function become more complex, current State Grid standards require that at least 365 days of data be frozen and stored every minute. This 365-day data set is 8MB or more in length, potentially including data related to electricity consumption, demand, voltage, current, power, frequency, harmonics, and fundamental frequency. Energy meters typically store this data according to protocols.

[0004] The applicant argues that, to meet the needs of users for tracking electricity bills, power supply bureaus for effective monitoring of power line loads, the accuracy and stability of electricity meters operating at maximum load, and the needs of power supply bureaus or manufacturers for on-site big data analysis, testing of object-oriented protocol-based electricity meters under application load stress is an inevitable trend. The object protocol referred to here is the protocol used by the electricity meter to store relevant data. The application load stress testing refers to measuring relevant load parameters, such as load curves, when the electricity meter is connected to a load, thereby generating data; this process is the testing. The performance of the electricity meter or the load can then be further assessed based on the test data.

[0005] Therefore, how to implement application load stress testing for object-oriented protocol energy meters is a technical problem that needs to be solved. Summary of the Invention

[0006] The purpose of this application is to provide an automatic testing method, a computer-readable storage medium, and an electronic device to solve the technical problem of how to implement testing of object-oriented protocol energy meters under application load pressure in the prior art.

[0007] To achieve the above objectives, the embodiments of this application adopt the following technical solutions.

[0008] In a first aspect, embodiments of this application provide an automatic testing method applied to a testing device for an electricity meter, wherein the testing device is communicatively connected to the electricity meter, and the automatic testing method includes:

[0009] Get the specified number of times;

[0010] Determine if the number of freezes is less than the specified number;

[0011] If the number of freezes is less than the specified number, the electricity meter time is set, and when the electricity meter time reaches the freeze time, the freeze data is stored. The steps of judging whether the number of freezes is less than the specified number and storing the freeze data are executed repeatedly until the number of freezes reaches the specified number.

[0012] If the number of freezes reaches the specified number, the electricity meter data will be read according to the specified reading range.

[0013] Optionally, the step of setting the electricity meter time and storing frozen data when the electricity meter time reaches the freeze time includes:

[0014] Set the electricity meter time to the preset initial time value and start timing simultaneously; obtain the delay time based on the timing.

[0015] When the electricity meter reaches the freeze time, the frozen data is stored.

[0016] If the delay time reaches a preset second time and the number of freezes is less than a specified number, the electricity meter time is set to the previously set time plus a preset first time, and timing begins. The delay time is obtained based on the timing, and the process of storing frozen data when the electricity meter time reaches the freeze time, and setting the electricity meter time to the previously set time plus a preset first time and timing begins, and obtaining the delay time based on the timing, is repeated until the number of freezes reaches the specified number.

[0017] Optionally, the first time includes multiple different values, and the value of the first time is different for different freeze types.

[0018] Optionally, the suitable range for the second time is 3 to 10 seconds.

[0019] Optionally, the initial time value can be multiple different initial time values, and the initial time value corresponding to different freeze types is different.

[0020] Optionally, the specified copying range includes a start time and an end time;

[0021] The steps for reading electricity meter data according to the specified reading range include: reading the electricity meter data between the start time and the end time based on the start time and end time.

[0022] Optionally, the specified copying range may also include a single copying time range;

[0023] The steps for reading electricity meter data according to the specified reading range include: filtering the electricity meter data between the start time and end time according to the single reading time range based on the start time and end time, and reading the selected electricity meter data.

[0024] Optionally, the specified copying range further includes a single copying interval, wherein the single copying interval is a natural number;

[0025] The steps for reading electricity meter data according to the specified reading range include: reading the electricity meter data between the start time and the end time at intervals according to the single reading interval, based on the start time and end time.

[0026] Secondly, embodiments of this application provide a computer-readable storage medium storing a computer program or instructions, which, when executed by a computing device, implements the automatic testing method of the first aspect.

[0027] Thirdly, embodiments of this application provide an electronic device, which includes a memory and a processor. The memory is electrically connected to the processor, and the memory stores an executable program. When the processor executes the executable program, it implements the automatic testing method of the first aspect.

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

[0029] This application's embodiments achieve rapid acquisition of frozen data by setting the time of the electricity meter, improving testing efficiency. Software-based data reading enables automated testing and automatic data recording, saving significant labor costs. The software can be installed on a computer without requiring changes to existing smart meter software and hardware. The computer's dynamic and flexible storage space further enables automatic visualization and data export on demand, improving testing efficiency, enhancing product component selection efficiency, and effectively shortening the R&D and testing cycle. The testing methods are shared across R&D teams, and the test design methodology is industry-leading, effectively verifying the reliability of electricity meter data storage and operational stability. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A schematic diagram of an electronic device provided in an embodiment of this application;

[0032] Figure 2 This application provides a schematic diagram of a communication connection between an electronic device and an energy meter.

[0033] Figure 3 This is a schematic diagram of an automatic testing method according to an embodiment of this application;

[0034] Figure 4 This is a schematic diagram illustrating one implementation of step S3 in an embodiment of this application. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of this application, not all embodiments. The components of the embodiments of this application described in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0037] In the description of this application, it should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The term "connection" should be interpreted broadly, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0038] The applicant discovered that testing an electricity meter requires following its normal operating procedure. This involves connecting the meter to a load according to a pre-programmed sequence to obtain data, such as load-related parameters. This pre-programmed sequence requires the meter's time display; the meter displays the current time, for example, indicating the year, month, hour, minute, and second.

[0039] When measuring load-related parameters, existing electricity meters generate data according to the meter's time. For example, if the meter's time is a certain year, month, day, hour, minute, and second, a data point can be generated at the 0th second of every minute. For example, a data point is generated at 2:05:00, and another data point is generated at 2:06:00, which is called minute freezing.

[0040] However, the applicant argues that waiting a full minute for a single data entry after a minute-based freeze is inefficient. Besides minute-based freezes, there are other time-based freeze types; for example, hourly freezes require a one-hour freeze cycle, and daily freezes require a one-day freeze cycle before a single data entry is generated, resulting in fewer data entries and lower efficiency.

[0041] Furthermore, dealing with large amounts of data requires manual reading and copying, which is highly inefficient. The applicant conceived of a solution: software that could automatically read and copy the data—this is the core concept of this application.

[0042] like Figure 1 As shown in the figure, this application provides an electronic device 10, which includes a memory 11 and a processor 12.

[0043] The memory 11 and processor 12 are electrically connected directly or indirectly to achieve data transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses or signal lines. The memory 11 stores computer programs or instructions, and the processor 12 executes various functional applications and data processing by running the software programs and modules stored in the memory 11, thereby realizing the automatic testing method in the embodiments of this application.

[0044] Understandable. Figure 1 The structure shown is for illustrative purposes only; the electronic device 10 may also include components that are more advanced than those shown. Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown. Figure 1 The components shown can be implemented using hardware, software, or a combination thereof.

[0045] Electronic device 10 can be a computer that can communicate with electricity meter 30, such as... Figure 2 This can be achieved using the existing communication interface used in electricity meters.

[0046] This application also provides a readable storage medium, which includes a computer program. When the computer program runs, it controls the electronic device 10 containing the readable storage medium to perform the following automatic testing method.

[0047] Please see Figure 3 This is a flowchart illustrating an automatic testing method implemented in an embodiment of this application. The method includes:

[0048] S1. Get the specified number of times; The specified number of times is a parameter related to the amount of data required. If more data is needed, the specified number of times should be higher. It can be manually entered according to the needs of this test.

[0049] S2. Determine if the number of freezes is less than the specified number; the number of freezes here refers to how many times the data has been frozen. Each freeze generates one or a set of data. The determination is to check whether enough data has been generated to meet the requirements.

[0050] S3. If the number of freezes is less than the specified number, set the electricity meter time, and when the electricity meter time reaches the freeze time, store the freeze data, and repeat the steps of judging whether the number of freezes is less than the specified number and storing the freeze data until the number of freezes reaches the specified number.

[0051] S4. If the number of freezes reaches the specified number, the electricity meter data will be read according to the specified reading range.

[0052] Setting the electricity meter time is a key aspect of this embodiment. The goal is to set the electricity meter time to a time close to the freeze time, for example, two seconds before the freeze time, so that frozen data can be obtained in just two seconds. Normal minute freezes require 60 seconds to obtain frozen data, while other freezes, such as hour freezes, take even longer.

[0053] Therefore, this is also a significant beneficial effect of the embodiments of this application: by setting the time of the electricity meter, frozen data can be obtained quickly, improving testing efficiency. Specifically, the electricity meter time is made to frequently cross the frozen time (usually at the top of the hour, such as freezing minutes at the zeroth second of each minute, freezing hours at the zeroth second of the first minute of each hour, etc.), quickly generating full-load frozen data. This operation supports plaintext and security settings and is compatible with the communication protocols DL / T 645 and DL / T698.45 issued by the State Grid. It can meet the automatic load pressure testing requirements of current State Grid 20 standard electricity meters, smart IoT electricity meters, and other applications.

[0054] The hardware costs nothing, while the software can be set to a user-friendly interface, with simple configuration, one-click operation, and parsing of time-stamped data stored in the electricity meter.

[0055] Another key aspect of this embodiment is automatic data reading, rather than manual reading. Specifically, in step S4, once the number of freezes reaches a specified number, it signifies the end of the data generation process. Then, the electricity meter data can be read according to the specified reading range. This reading step is pre-configured in the software; no manual reading is required, nor is it necessary to manually determine whether the data generation process has ended, i.e., whether the desired data or data volume has been generated.

[0056] Therefore, this is another important beneficial effect of the embodiments of this application: through software copying, automatic testing and automatic copying are achieved. Automatic copying is much more efficient than manual copying and saves a lot of labor costs. This solution has a wide range of applications, not only suitable for R&D and testing personnel, but also meeting the big data application needs of technical service personnel for fault location.

[0057] Without the software provided in this embodiment, the following difficulties would be encountered:

[0058] 1) The amount of data to be read is large. The standard specifications of electricity meters limit the length of each communication frame (e.g., RS485 standard specifications limit the length of each communication frame to 512 bytes, carrier 512 bytes, infrared 200 bytes, Bluetooth 512 bytes), and the total length of APDU for each communication frame is limited in a single reading (e.g., 2000 bytes). This makes it impossible for the electricity meter itself to complete the reading of the required stored data in one go (the standard specifications stipulate that different data for 365 days are frozen and stored every minute, which is more than 8M bytes). It is necessary to split the data into multiple nodes, and even more nodes are needed for secure encryption of the data.

[0059] 2) Big data analysis involves many nodes and relies on manual analysis, which increases the complexity of the problem and consumes a lot of time and resources;

[0060] 3) Manually piecing together data for analysis is prone to errors and omissions, hindering one-time analysis and increasing the complexity of data analysis.

[0061] The above describes the difficulties faced by existing technologies without the software provided in this embodiment. As can be seen, this embodiment saves a significant amount of manpower and cost in analyzing data.

[0062] In step S3, the step of setting the electricity meter time and storing the frozen data when the electricity meter time reaches the freeze time can be implemented in various ways, for example... Figure 4 It can be:

[0063] S3-1. Set the electricity meter time to the preset initial time value and start timing simultaneously, then obtain the delay time based on the timing.

[0064] S3-2. Store frozen data when the electricity meter time reaches the freeze time;

[0065] S3-3. When the delay time reaches the preset second time, and the number of freezes is less than the specified number, the electricity meter time is set to the previously set time plus the preset first time, and timing starts. The delay time is obtained based on the timing, and the steps of "storing freeze data when the electricity meter time reaches the freeze time, setting the electricity meter time to the previously set time plus the preset first time when the delay time reaches the preset second time, and timing starts, and obtaining the delay time based on the timing" are executed repeatedly until the number of freezes reaches the specified number.

[0066] For example, if the electricity meter time is 2:05:02, and the first time for the minute-frozen data is 60 seconds, then in step S3-1, the host computer can specify an initial time value of 2:05:58 (the preset initial time value is the last 58 seconds, and the other minutes and hours can be left unchanged) to set the electricity meter time to 2:05:58. Then, it only takes 2 seconds to get the data frozen at 2:06:00.

[0067] On the other hand, when the electricity meter shows 2:05:58, the timer starts counting from 0:00:00. The timer's duration is called the delay time.

[0068] The data was frozen at 2:06:00. At this time, the timer was 0:00:02, meaning the delay was 2 seconds.

[0069] The second timeout can be set to 4 seconds. When the delay reaches 4 seconds (timer time: 0:00:04, meter time: 2:06:02), if the number of freezes is less than the specified number, the process will repeatedly set the meter time to the previously set time plus a preset first timeout of 60 seconds. The previously set time was 2:05:58, so adding 60 seconds gives the meter time 2:06:58. Two seconds later, the data will be frozen at 2:07:00. At 2:07:02, if the number of freezes is less than the specified number, the meter time will continue to be set to the previously set time plus the preset first timeout… until the specified number of freezes is reached.

[0070] The specified number of times can be understood as a requirement for the amount of data. The specified number of times can also be understood as the number of loops. If the specified number of times is n, then the loop will run n times and freeze n times. The larger n is, the more data will be generated by freezing.

[0071] The specified number of iterations can be either a specific natural number entered directly by the user, or a rough level entered by the user. The software then determines the number of iterations based on the level, meaning the software determines the specified number of iterations based on the user-input level. For example, the specified number of iterations is 1000 for level A and 10000 for level B.

[0072] The examples above show that for data frozen in minutes, the first time can be set to approximately 60 seconds, and the second time to approximately 4 seconds. For data frozen in 60 minutes, the first time can be set to 60 minutes, and the second time to 4 seconds. For data frozen in hours, days, months, or other time types, the first time can be flexibly set as needed.

[0073] In other words, in the software, the first time includes multiple different values. The values ​​of the first time are different for different freeze types, and the values ​​of the first time can vary greatly.

[0074] The appropriate range for the second time interval is relatively small, recommended to be within 10 seconds, ideally between 3 and 10 seconds. Too long a delay will result in excessively long data freezing time; too short a delay may cause the electricity meter to be unable to complete the freezing and storage of data, resulting in missed recording of frozen data at a certain time point.

[0075] By setting appropriate first and second times, the 15-minute interval frozen data that would normally take 365 days to generate can be generated in 2 days, and the parsing of 365 days of data can be completed in 1 day; 365 days of data frozen at 1-minute intervals can be generated in 21 days with zero errors, saving manpower and time costs.

[0076] Depending on the type of freeze required, before setting the electricity meter time to the first preset time by adding the previously set time, an initial time value for the electricity meter needs to be set.

[0077] For example, if the freeze type is daily freeze, and the current meter time is 20:00:00, there are still 4 hours until 24:00:00 (0:00:00), meaning it will take another 4 hours for the freeze to occur. In this case, the meter time can be directly set to 23:59:58, which will set the freeze time in just 2 seconds. Here, 23:59:58 is the initial time value set for the meter. The initial time value can be a few seconds before the freeze time.

[0078] For a freeze type of hourly freeze, for example, if the current time on the electricity meter is 20:30:00, the electricity meter time can be directly set to 20:59:58.

[0079] For a freeze type of minute freeze, for example, if the current time on the electricity meter is 20:31:01, the time on the electricity meter can be directly set to 20:31:58.

[0080] As can be seen, the initial time value is different depending on the freeze type; that is, the initial time value is different for different freeze types.

[0081] In other words, you can set the following steps in the automated testing method: obtain the freeze type, and get the corresponding first time value and initial time value based on the freeze type.

[0082] After setting the initial time value, the process can proceed smoothly according to the cycle of delaying the second time, freezing, accumulating the first time value, and delaying the second time.

[0083] Once the loop completes, you will have the necessary data, and you can proceed to the next step.

[0084] Copying.

[0085] In step S4, the specified reading range can be all data from the start time to the end time. Either the start time or the end time can be a default value or manually specified. The specified reading range can include the start time and the end time. The steps for reading electricity meter data according to the specified reading range can include: reading the electricity meter data between the start time and the end time based on the start time and the end time.

[0086] Reading electricity meter data between the start and end times can be done in three ways: 1) reading all electricity meter data between the start and end times; 2) reading electricity meter data within a specific time range between the start and end times, i.e., filtering the electricity meter data between the start and end times according to a single reading time range and reading the filtered electricity meter data; or 3) filtering and reading the electricity meter data between the start and end times at specified intervals.

[0087] For 2), specifically, the range of a single copying session can be the range before and after a time point every 15 minutes, for example:

[0088] The range before and after the time points 1:00:00, 1:15:00, 1:30:00, 1:45:00, 2:00:00, etc., i.e.:

[0089] 0:59:58 to 1:00:02, 1:14:58 to 1:15:02, 1:29:58 to 1:30:02, 1:44:58 to 1:45:02, 1:59:58 to 2:00:02.

[0090] For 3), specifically, the interval between each copy can be a natural number. If the interval is 0, it means that all data is copied. If the interval is 1, then every other data point is copied. If the interval is 2, then every two data points are copied. For example, if the data is 2, 4, 5, 7, 8, 9, 1, 3, then every two data points copied will result in the data 2, 7, 1.

[0091] One implementation method is as follows:

[0092] The software allows you to set freeze types, including minute freeze, hour freeze, and day freeze.

[0093] The software allows you to set options for copying methods, including specifying a time range for copying.

[0094] In the software, set the input boxes for single copying interval, start time Tstart, end time Tend, and single copying time range Trange.

[0095] If the interval between each copy is 0, then all the data obtained will be copied. The obtained data is generated through the following steps:

[0096] S01. Assign the start time Ts = Tstart and the end time Te =

[0097] MIN(Ts+Trange,Tend) and send it to the electricity meter.

[0098] S02. The energy meter generates a data frame based on the energy meter data between the start time Ts and the end time Te, and sends it to the testing device.

[0099] S03. The testing device uses a program to parse the electricity meter data in the returned data frame. If the parsed electricity meter data is 0, that is, there is no electricity meter data in the returned data frame, then jump to step S04; otherwise, jump to step S05.

[0100] S04. Assign the end time Te to the start time Ts, that is, let Ts = Te, and then assign Te = MIN(Ts + Trange, Tend). If Ts is less than Tend, jump to step S02 to execute; otherwise, end the copying and jump to step S06.

[0101] S05. Cache the parsed electricity meter data and record the last record time Trecord in this response data. Reassign the start time Ts and Te, setting Ts = Trecord + 1 second and Te = MIN(Ts + Trange, Tend). If Ts is less than Tend, jump to step S02 to execute; otherwise, end the reading and jump to step S06.

[0102] S06. Displaying or saving the cached parsed data as needed can further enable visualized data analysis, such as forming a curve with time on the horizontal axis and electricity meter data on the vertical axis.

[0103] In summary, this application proposes an automated testing method, storage medium, and electronic device. By setting the time of the electricity meter, frozen data can be obtained quickly, improving testing efficiency. Through software-based data reading, automated testing and automatic data reading are achieved, saving significant labor costs.

[0104] The apparatus and system embodiments described above are merely illustrative. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement these embodiments without any creative effort.

[0105] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An automatic testing method, characterized by, The application relates to a testing device applied to an electric energy meter, wherein the testing device is in communication connection with the electric energy meter, and the automatic testing method comprises the following steps: acquiring a specified number of times; judging whether the number of frozen times is less than the specified number of times; if the number of frozen times is less than the specified number of times, setting the electric energy meter time, storing frozen data when the electric energy meter time reaches the frozen time, and repeatedly executing the steps of judging whether the number of frozen times is less than the specified number of times and storing frozen data until the number of frozen times reaches the specified number of times; if the number of frozen times reaches the specified number of times, reading the electric energy meter data according to a specified reading range; the step of setting the electric energy meter time and storing frozen data when the electric energy meter time reaches the frozen time comprises the following steps: setting the electric energy meter time as a preset initial time value and starting timing, and obtaining a delay time according to the timing; storing frozen data when the electric energy meter time reaches the frozen time; when the delay time reaches a preset second time and the number of frozen times is less than the specified number of times, setting the electric energy meter time as the last set time plus a preset first time, starting timing, obtaining a delay time according to the timing, and repeatedly executing the steps of storing frozen data when the electric energy meter time reaches the frozen time, setting the electric energy meter time as the last set time plus the preset first time when the delay time reaches the preset second time and the number of frozen times is less than the specified number of times, and starting timing until the number of frozen times reaches the specified number of times.

2. The automatic testing method of claim 1, wherein, The first time comprises a plurality of different values, and the values of the first time corresponding to different frozen types are different.

3. The automatic testing method of claim 1, wherein, The second time is 3-10 seconds.

4. The automatic testing method of claim 1, wherein, The initial time value is a plurality of different initial time values, and the initial time values corresponding to different frozen types are different.

5. The automatic testing method of claim 1, wherein, The specified reading range comprises a start time and an end time. The step of reading the electric energy meter data according to the specified reading range comprises reading the electric energy meter data between the start time and the end time according to the start time and the end time.

6. The automatic testing method of claim 5, wherein, The specified reading range further comprises a single reading time range. The step of reading the electric energy meter data according to the specified reading range comprises screening the electric energy meter data between the start time and the end time according to the single reading time range, and reading the screened electric energy meter data.

7. The automatic testing method of claim 5, wherein, The specified reading range further comprises a single reading interval, and the single reading interval is a natural number. The step of reading the electric energy meter data according to the specified reading range comprises interval reading the electric energy meter data between the start time and the end time according to the single reading interval.

8. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program or instructions, and when the computer program or instructions are executed by a computing device, the method in any one of claims 1-7 is realized.

9. An electronic device, comprising: The electronic device comprises a memory and a processor, the memory is in electrical connection with the processor, the memory stores an executable program, and the processor realizes the method in any one of claims 1-7 when executing the executable program.

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