Derivation tracking method based on control logic data type conversion

Abstract

The invention discloses a derivation tracking method based on control logic data type conversion, and aims to solve the problem of data loss risk or precision loss during superposition of a plurality of arithmetic units in the conventional common data type conversion method, which comprises the following steps of: simplifying the summation operation of a configuration bit number and representing the summation operation into a form of a plurality of arithmetic units; sorting the arithmetic units according to the execution sequence; sequentially setting data type labels among the arithmetic units according to the sequence, and determining the content of the data type labels according to the input or output of the arithmetic units; unknown data type labels are completed according to a completion rule, and the data type of the transfer temporary data is deduced according to the completed data type labels; and confirming the unknown data type and the data type of the transfer temporary data according to a first confirmation rule, and judging whether a data loss risk exists or not. According to the method, memory resources of the system can be effectively saved, and precision loss in the type conversion process can be accurately alarmed.

Description

Technical Field

[0001] The present invention relates to the technical field of data type conversion, and in particular to a derivation and tracking method based on control logic data type conversion. Background Art

[0002] In process control systems, various types of configuration software and control logic programming languages ​​are often used. When using these programming languages, it is often necessary to perform superposition calculations on some computing units. When a single computing unit has multiple inputs or multiple outputs, or multiple computing units are connected in series, if the data types between the computing units are not uniform or the data types of multiple inputs are not uniform, data type conversion is required. When the data type conversion is wrong or the data precision is lost, it will cause confusion in the execution logic of the control system.

[0003] Currently, there are two commonly used data type conversion methods: 1. Convert the data types of all computing units to the maximum data type supported by the system (such as double-precision floating point, which is used as an example below) for calculation. When connecting various computing units, it is inevitable to create many temporary variables for data transfer. These temporary variables must also be double-precision floating points, which will cause a large waste of controller system memory resources. In addition, when the control logic is finally output, there may be a risk of data loss when the double-precision floating point is converted to a non-double-precision floating point output type.

[0004] 2. The output data type of each operation unit is derived from the input data type of each operation unit. For example, if both inputs of an operation unit are 16-bit integers, the derived output is also a 16-bit integer. If the actual output is less than a 16-bit integer, an error is reported and the created transfer variable is also a 16-bit integer. Although this method solves the problem of system memory waste, it cannot solve the problem of precision loss when multiple operation units are superimposed, nor can it solve the problem of data conversion when the input type is unknown. For example, if the two inputs are constants 1 and 100, it cannot be deduced that 1 and 100 should be converted into 16-bit integers or 16-bit unsigned integers. Summary of the invention

[0005] The present invention solves the problem of data loss risk or precision loss when multiple operation units are superimposed in the currently commonly used data type conversion methods, and proposes a derivation and tracking method based on control logic data type conversion, which effectively solves the problem that the data type of each operation unit component cannot be confirmed in the current solution, resulting in loss of precision during data type conversion, and accurately alarms the loss of precision during the type conversion process.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: a derivation and tracking method based on control logic data type conversion, characterized in that it includes the following steps: S1, simplifying the sum operation of the configuration bit number into a form of several operation units, and sorting the operation units in the execution order; S2, setting data type labels in sequence between the operation units according to the order, and determining the content of the data type label according to the input or output of the operation unit; S3, completing the unknown data type label according to the completion rule, and deducing the data type of the transit temporary data according to the completed data type label; S4, confirming the data type of the unknown data and the data type of the transit temporary data according to the first confirmation rule to determine whether there is a risk of data loss.

[0007] In the present technical solution, a number of operation units are first generated, and the operation units are sorted and connected according to the execution order, a data type label is placed between each operation unit, and the content of the data type label is filled in according to the corresponding data type label filling rule. After filling in the content of the data type label, the content is completed to derive the simplest data type; finally, the first confirmation rule is used to verify and confirm the data type to prevent the data from losing precision during type conversion, and to accurately alarm the loss of precision during the data type conversion process.

[0008] The present invention is further configured such that: the operation unit in step S1 has a plurality of inputs, and the operation unit outputting the final result has a plurality of outputs of fixed data types.

[0009] In this technical solution, the input of each operation unit may have a fixed data type or an uncertain data type.

[0010] The present invention is further configured as follows: when the operation unit is not an operation unit that outputs a final result, its output end creates transit temporary data with an uncertain data type.

[0011] In the technical solution, the creation of temporary transfer data involved in the above process can facilitate data transfer in the control logic.

[0012] The present invention is further configured as follows: the data type label of step S2 includes a forward value label and a reverse value label, the forward value label derives the output data type of the previous operation unit according to the input, and the reverse value label derives the input data type of the next operation unit according to the output.

[0013] In this technical solution, according to the order of the operation units, corresponding data type labels are set on the connection nodes where the output and input have a connection relationship, and the data type labels mainly include forward value labels and reverse value labels.

[0014] The present invention is further configured as follows: determining the content of the data type label according to the input or output of the operation unit includes: S21, when the operation unit has multiple inputs, the maximum type of the input data is the output type of the operation unit, and this type is determined as the positive value label content; S22, when the operation unit has multiple outputs, the minimum type of the output data is the input type of the operation unit, and this type is determined as the positive value label content.

[0015] In this technical solution, the corresponding positive value and reverse value are confirmed and filled in according to the above rules.

[0016] The present invention is further configured such that when a positive value or a reverse value cannot be derived, the corresponding positive value label content or the reverse value label content is filled in as unknown.

[0017] In this technical solution, after the forward value or the reverse value cannot be derived, subsequent completion rules need to be used to complete the unknown forward value and reverse value.

[0018] The present invention is further configured as follows: the completion rule is: for a data type determined by a same data type label, if both the forward value and the reverse value are unknown, the forward value and the reverse value are recalculated in a first-input-then-output manner, and the forward value label content and the reverse value label content are completed according to the rule.

[0019] In this technical solution, through the above-mentioned completion rules, the data type conversion rules in the control logic can be accurately derived, and the simplest data type can be derived.

[0020] The present invention is further configured as follows: the first confirmation rule is: when the reverse value type of the same data type label is greater than or equal to the forward value type, the unknown type is the reverse value type; if the reverse value type is smaller than the forward value type, this conversion has a risk of data loss.

[0021] In this technical solution, after the data type of the transit temporary data is derived in step S3, the unknown type and the transit temporary data are confirmed to determine whether there is a risk of data loss and report an error.

[0022] The present invention is further configured such that: the transit temporary data is a temporary intermediate variable generated between the operation units.

[0023] The temporary data in transit obtained by the technical solution occupies less memory and can save a lot of memory.

[0024] The present invention is further configured such that: the comparison of the data types is specifically a comparison of the number of bits of the data types.

[0025] In this technical solution, different data types have different numbers of bits.

[0026] The present invention can bring the following beneficial effects: 1. The present invention relates to a derivation and tracking method based on control logic data type conversion, which can effectively solve the problem that the data types of various operation unit components cannot be confirmed in the current solution, resulting in loss of precision during data type conversion, and accurately alarm the loss of precision during type conversion; 2. The present invention can effectively save the memory resources of the system; the present application can accurately deduce the types of intermediate variables and constants between various operation units. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a flowchart of a derivation and tracking method based on control logic data type conversion in this application.

[0028] Figure 2 A logic block diagram for summing multiple variables when programming control logic.

[0029] Figure 3 Block diagram of the arithmetic unit when programming the control logic.

[0030] Figure 4 This is the block diagram of the sorted operation unit.

[0031] Figure 5 This is the block diagram of the operation unit after adding the data type label.

[0032] Figure 6 This is the block diagram of the operation unit after filling in the positive value.

[0033] Figure 7 This is the block diagram of the operation unit after filling in the reverse value.

[0034] Figure 8 A block diagram of the operation unit that completes the data type label.

[0035] Fig. 9 This is the block diagram of the operation unit after all types are determined.

[0036] Fig.10 A block diagram showing a type conversion failure.

[0037] Fig.11 Resulting diagram of data type conversion when programming control logic. DETAILED DESCRIPTION

[0038] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific implementation method described herein is only an optimal embodiment of the present invention, which is only used to explain the present invention and does not limit the scope of protection of the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0039] The present application discloses a derivation and tracing method based on control logic data type conversion, which is applicable to control system configuration software. For configuration software, it is a special software that can mainly perform data acquisition and process control, and serve as a development tool or development environment for the upper computer human-machine interface of the control system; for control logic, it can realize system control, and determine the required operations and outputs through logical operations and decisions; for data types, an abstract description of the structure and characteristics of data is defined in a programming language; for type conversion, it is an automatic (implicit conversion) or forced (explicit conversion) conversion when converting a value of one type to another type.

[0040] Example 1 In combination with the background technology, it can be seen that the existing algorithms mainly have the following problems.

[0041] 1. When creating temporary transfers between multiple computing units, the variable data type is too large, and system memory resources are wasted unnecessarily.

[0042] 2. When the input data type of the starting operation unit is a constant, the converted data type is unclear, resulting in loss of sign or precision.

[0043] 3. When multiple operation units are superimposed, the data type of each unit is calculated independently, resulting in unclear conversion of data types of each operation unit and data loss.

[0044] 4. When performing data type conversion, the judgment method is too complicated, resulting in slow compilation of control logic and low execution efficiency.

[0045] refer to Figure 2 In a specific implementation, when programming the configuration control logic of the process control system, it is necessary to implement the sum operation of the configuration bit number NTAG1 (16-bit integer) / NTAG2 (8-bit integer) / NTAG3 (8-bit integer) / NTAG4 (8-bit integer) / 10 (constant) / -10 (8-bit integer) variables and constants, and assign the sum result to the bit number NTAG5.

[0046] The general operation logic is: create a temporary double-precision floating-point temporary variable, specifically: TEMP1 / TEMP2 / TEMP3 / TEMP4 / TEMP5.

[0047] And the above variables have the following relationship: 1. TEMP1=NTAG1+NTAG2; 2. TEMP2=10+(-10); 3. TEMP4=NTAG3+NTAG4; 4. TEMP3=TEMP1+TEMP2; 5. NTAG5=TEMP4+TEMP3; After five steps of calculation, the value of NTAG5 is obtained. Four temporary variables, TMEP1 to TAMP4, need to be created. Each temporary variable occupies 8 bytes, totaling 32 bytes of memory. There is no need for complex logic to deduce the type of temporary variables, but the memory space is seriously wasted.

[0048] Or the commonly used optimization algorithm can infer that TEMP1 should be INT (16-bit integer) through the types of NTAG1 and NTAG2, but it is impossible to infer the type of TEMP2 through the constants 10 and -10. If you want to infer the data type of TEMP2, you need to judge the entire logical link, which takes a long time to infer. Moreover, the type of NTAG5 is determined, and it is difficult to determine whether the temporary variables TEMP4 and TEMP3 can assign values ​​to NTAG5 without losing data.

[0049] This embodiment proposes a derivation and tracking method based on control logic data type conversion, which can quickly derive the simplest data type of the above TEMP1 / TEMP2 / TEMP3 / TEMP4 / TEMP5, and can accurately determine whether data loss occurs when each data type is converted. Figure 1 , which includes the following steps.

[0050] Step S1, first simplifying the sum operation of the configuration bit number into a form of a plurality of operation units, and then sorting the operation units, specifically sorting them according to the execution order.

[0051] In this embodiment, operation unit A, operation unit B, operation unit C, operation unit D and operation unit E are included, wherein operation unit A is connected to operation unit C, operation unit A is connected to operation unit C, operation unit C is connected to operation unit E, operation unit D is connected to operation unit E, and operation unit E is an operation unit that outputs the final result.

[0052] In step S1, each operation unit has multiple inputs, and the operation unit that outputs the final result has multiple outputs of fixed data types.

[0053] In this technical solution, the input of each operation unit may have a fixed data type or an uncertain data type.

[0054] When the operation unit is not an operation unit that outputs a final result, the output end of the operation unit creates transit temporary data, and the transit temporary data is data of uncertain data type.

[0055] In the technical solution, the creation of temporary transfer data involved in the above process can facilitate data transfer in the control logic.

[0056] For step S1, in more detail, the summation calculation of the above control logic is simplified into a general operation unit, such as Figure 3 As shown, the control program consists of a total of 5 operation units AE, each of which has multiple inputs, which may have fixed data types or uncertain data types (such as constants). The final operation unit E has multiple outputs (with fixed data types), among which the outputs of operation units A and B are the inputs of operation unit C, which are connected by lines. After operation units A and B operate, temporary variables (with uncertain data types) need to be created in the control logic for data transfer.

[0057] refer to Figure 4 , sort these operation units in the order of execution. For example, the output results of operation unit A and operation unit B point to operation unit C, and the operation results of operation unit C and operation unit D are E. The order encoding of these operation units is A (1), B (2), C (3), D (4), E (5).

[0058] Step S2, after the sorting is completed, corresponding data type labels are sequentially set between adjacent operation units, and the content of the data type label is determined according to the output or input type of the operation unit.

[0059] In the above steps, the data type labels mainly include forward value labels and reverse value labels, wherein the forward value label can deduce the output data type of the operation unit according to the input of the previous operation unit, and the reverse value label can deduce the data type of the next operation unit according to the output of the next operation unit.

[0060] In this technical solution, according to the order of the operation units, corresponding data type labels are set on the connection nodes where the output and input have a connection relationship, and the data type labels mainly include forward value labels and reverse value labels.

[0061] In the above steps, how to determine the content of the data type label according to the output or input type of the operation unit specifically includes the following sub-steps.

[0062] Step S21, when there are several inputs in the operation unit, the maximum type of the input data is the output type of the operation unit, and then the type is determined and filled in as the positive value label content.

[0063] Step S22, when the operation unit has several outputs, the minimum type of the output data is the input type of the operation unit, and then the type is determined and filled in as the reverse value label content.

[0064] In this technical solution, the corresponding positive value and reverse value are confirmed and filled in according to the above rules.

[0065] When the above rules cannot be derived to obtain a positive value or a reverse value, the corresponding positive value label content or reverse value label content needs to be filled in as unknown.

[0066] In this technical solution, after the forward value or the reverse value cannot be derived, subsequent completion rules need to be used to complete the unknown forward value and reverse value.

[0067] For more details, see Figure 5 According to the order of sorting, data type labels are set on the connection nodes where the output and input have a connection relationship. The specific expression is <forward value, reverse value> label. Specifically, two data type labels are added between the output of operation unit A and operation unit B and the input of operation unit C. The forward value of the data type label refers to the output of the operation unit inferred from the input of the previous operation unit (for example, the output data type of operation unit A is inferred from its input), and the reverse value refers to the input data type of the next operation unit inferred from its output (for example, the input type of operation unit C is inferred from the output of operation unit C).

[0068] refer to Figure 6 , fill in the positive value. When a computing unit has multiple inputs, the largest type of input data (the type that can represent a larger data range) is the output type of this unit. Fill in this type in the positive value. When the positive value cannot be calculated, fill in unknown. Filling in the positive value according to this rule can ensure that there is no data loss between input and output, such as Figure 6 As shown, the input of operation unit A is INT (2-byte integer)\BYTE (1-byte unsigned integer), so its forward value is inferred to be INT. The input of operation unit B is a constant whose type cannot be determined, so the forward value is unknown. The input of operation unit C is unknown, so its output forward value is unknown, and the output forward value of operation unit D is BYTE.

[0069] refer to Figure 7, fill in the reverse value. When an operation unit has multiple outputs, the minimum type of the output data (the type that can represent a smaller data range) is the input type of this unit, so as to ensure that there is no data loss between input and output. When the reverse value cannot be calculated, fill in unknown. Fill in the reverse value according to this rule. If the output of operation unit E is REAL (4-byte floating point)\INT, then its reverse value is calculated to be INT. If the forward value of operation unit C is unknown, its reverse value is also unknown.

[0070] After completing the filling of the above-mentioned forward value and reverse value, proceed to step S3.

[0071] Step S3, completing the unknown data type label according to the completion rule, and deriving the data type of the transit temporary data according to the completed data type label.

[0072] The completion rules are more detailed and include the following specific contents: for the data type determined by the same data type label, if both the forward value and the reverse value are unknown, the forward value and the reverse value are recalculated in the manner of input first and then output, and the forward value label content and the reverse value label content are completed according to the rule.

[0073] In this technical solution, through the above-mentioned completion rules, the data type conversion rules in the control logic can be accurately derived, and the simplest data type can be derived.

[0074] refer to Figure 8 , complete the unknown positive and negative values ​​according to the completion rules. For example, the label between operation unit C and operation unit E has an unknown positive value and a negative value of INT, so the positive value is INT; the positive value between operation unit A and operation unit C is INT, so the negative value is INT; the positive and negative values ​​between operation unit B and operation unit C are both unknown, and the input of operation unit B is also unknown. Then, the negative value (input) is inferred to be INT based on the positive value (output) of operation unit C, and the positive value of this label is also INT, so it is inferred that the input of operation unit B is all INT type.

[0075] Through the above deduction, the data type conversion rules in the control logic can be accurately deduced and the simplest data type can be derived. For example, it can be deduced that TEMP1 is of INT type, TEMP2 is of INT type, TEMP3 is of INT type, and TEMP4 is of BYTE type. The total memory of the four temporary variables is 9 bytes, which saves more than 50% of memory compared to the 32 bytes of the previous solution. It can also be accurately deduced that the types of constants 10 and -10 should also be INT types, solving the problem that the data type of constants cannot be confirmed.

[0076] Step S4: confirm the data type of unknown data and the data type of transit temporary data according to the first confirmation rule to determine whether there is a risk of data loss.

[0077] The transit temporary data are temporary intermediate variables generated between the computing units. The transit temporary data obtained by the technical solution takes up less memory and can save a lot of memory.

[0078] For the first confirmation rule, the specific process is as follows: When the reverse value type of the same data type label is greater than or equal to the forward value type, the unknown type is the reverse value type. If the reverse value type is less than the forward value type, this conversion has the risk of data loss.

[0079] In this technical solution, after the data type of the transit temporary data is derived in step S3, the unknown type and the transit temporary data are confirmed to determine whether there is a risk of data loss and report an error.

[0080] The above-mentioned comparison of data types is specifically performed by comparing the positions of the data types. In the present technical solution, the number of bits of different data types is different.

[0081] refer to Fig. 9 , Fig.10 and Fig.11 , confirm the data type of unknown type and transit temporary data. The confirmation rule is that when the type of the reverse value of the same data label is greater than or equal to the type of the forward value, the unknown type is the reverse value type. If the reverse value type is less than the forward value type, this conversion has the risk of data loss and an error needs to be reported.

[0082] According to the first confirmation rule above, it can be determined that the intermediate variable type between operation unit A and operation unit C is INT, the type between operation unit C and operation unit E is INT, and the type of the intermediate variable between operation unit D and operation unit E is BYTE. Fig. 9 As shown in the figure, if the input type of operation unit D is REAL and BYTE, the forward value between operation unit D and operation unit E is calculated to be REAL, and the reverse value is INT. The type of the reverse value is smaller than the type of the forward value, so there is a risk of data loss in this conversion. This method can effectively solve the problem that the data type of each operation unit component cannot be confirmed in the existing solution, resulting in loss of precision during data type conversion, and accurately alarm the loss of precision during type conversion.

[0083] In the present technical solution, a number of operation units are first generated, and the operation units are sorted and connected according to the execution order, a data type label is placed between each operation unit, and the content of the data type label is filled in according to the corresponding data type label filling rule. After filling in the content of the data type label, the content is completed to derive the simplest data type; finally, the first confirmation rule is used to verify and confirm the data type to prevent the data from losing precision during type conversion, and to accurately alarm the loss of precision during the data type conversion process.

[0084] The derivation tracking method of the present application provides a way to quickly confirm the data type of temporary intermediate variables created between operation units when programming control logic. The method of the present application can accurately and efficiently identify the unconfirmed data types between operation units, reducing the occupation of system memory resources; and by combining forward derivation with reverse derivation, it can not only quickly derive the type of conversion but also identify the data loss problem during the type conversion process.

[0085] The present application provides a method for quickly calculating the data type that needs to be converted for each operation unit when multiple operation units are superimposed for calculation during configuration control logic programming of a process control system, which mainly has the following advantages.

[0086] 1. It can effectively save system memory resources; this application can accurately infer the types of intermediate variables and constants between various computing units. The more precise the type, the smaller the type of temporary variables created. Creating variables with smaller memory means saving more system memory resources.

[0087] 2. It has high scalability; the derivation and tracking method of the present application has clear logic and can adapt to the type of inference of various operation logics.

[0088] 3. The calculation efficiency is high. When calculating the entire control logic, it only needs to calculate the preceding item once and the succeeding item once to calculate the uncertain data types in all logics.

[0089] 4. It has an error-correcting function, which can accurately locate the conversion errors of each calculation unit during the calculation process, and can deduce the errors during the derivation and calculation process, with high security.

[0090] Example 2 On the basis of embodiment 1, a derivation tracking system based on control logic data type conversion is also proposed, in which a number of functional modules are included, and the functional modules respectively include a first functional module, a second functional module, a third functional module and a fourth functional module, the first functional module can execute step S1 in the above embodiment 1; the second functional module can execute step S2 in the above embodiment 1, the third functional module can execute step S3 in the above embodiment 1; the fourth functional module can execute step S4 in the above embodiment 1. These functional modules can execute steps S1 to S4 in the above embodiment 1.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention and should be included in the scope of the claims of the present invention.

Claims

1. A derivation and tracking method based on control logic data type conversion, characterized in that: The following steps are involved: S1, simplifying the sum operation of the configuration bit number into a form of several operation units, and sorting the operation units in the execution order; S2, setting data type labels in sequence between the operation units according to the order, and determining the content of the data type label according to the input or output of the operation unit; S3, completing the unknown data type label according to the completion rule, and deducing the data type of the transit temporary data according to the completed data type label; S4, confirming the data type of the unknown data and the data type of the transit temporary data according to the first confirmation rule to determine whether there is a risk of data loss.

2. A derivation and tracing method based on control logic data type conversion according to claim 1, characterized in that: The operation unit in step S1 has several inputs, and the operation unit that outputs the final result has several outputs of fixed data types.

3. The derivation and tracking method based on control logic data type conversion according to claim 2 is characterized in that: When the operation unit is not an operation unit that outputs a final result, its output terminal creates transit temporary data with uncertain data type.

4. A derivation and tracking method based on control logic data type conversion according to claim 1, 2 or 3, characterized in that: The data type label of step S2 includes a forward value label and a reverse value label. The forward value label derives the output data type of the previous operation unit according to the input, and the reverse value label derives the input data type of the next operation unit according to the output.

5. The derivation and tracing method based on control logic data type conversion according to claim 4 is characterized in that: The determining the content of the data type label according to the input or output of the operation unit includes: S21, when the operation unit has multiple inputs, the maximum type of the input data is the output type of the operation unit, and this type is determined as the positive value label content; S22, when the operation unit has multiple outputs, the minimum type of the output data is the input type of the operation unit, and this type is determined as the positive value label content.

6. A derivation and tracing method based on control logic data type conversion according to claim 5, characterized in that: When the positive value or the reverse value cannot be derived, the corresponding positive value label content or the reverse value label content is filled in as unknown.

7. A derivation and tracking method based on control logic data type conversion according to claim 1 or 6, characterized in that: The completion rule is: for the data type determined by the same data type label, if both the forward value and the reverse value are unknown, the forward value and the reverse value are recalculated in the manner of input first and then output, and the forward value label content and the reverse value label content are completed according to this rule.

8. A derivation and tracking method based on control logic data type conversion according to claim 1, 2 or 3, characterized in that: The first confirmation rule is: when the reverse value type of the same data type label is greater than or equal to the forward value type, the unknown type is the reverse value type. If the reverse value type is less than the forward value type, this conversion has the risk of data loss.

9. The derivation and tracing method based on control logic data type conversion according to claim 1, characterized in that: The transit temporary data are temporary intermediate variables generated between the computing units.

10. The derivation and tracing method based on control logic data type conversion according to claim 8, characterized in that: The comparison of the data types is specifically a comparison between the number of bits of the data types.

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