CN117193719A - PLC standardized program development method for object-oriented programming - Google Patents

Abstract

The invention discloses an object-oriented programming PLC standardized program development method. The invention belongs to the technical field of PLC programs, and specifically relates to an object-oriented programming PLC standardized program development method. Specific steps include: equipment analysis, electrical parameter table, underlying data, control objects, object collection, process collection, variable process program, process execution, and state machine. According to the method provided by the invention, a set of PLC standardized programs can be compatible with one or more series of equipment, can add non-standard requirements to the program in a parameterized form, and expand the scope of equipment use. The standardized program written in an object-oriented programming manner, It has higher readability, good scalability, easy upgrades, and the application of variable process control strategies to achieve flexible control, products can be quickly switched, and the program can be parameterized, modularized, and standardized.

Description

An object-oriented programming method for PLC standardized program development

Technical field

The invention belongs to the technical field of PLC programs, and specifically relates to an object-oriented programming PLC standardized program development method.

Background technique

With the rapid development of microprocessors, computers and digital communication technology, computer control has been extended to almost all industrial fields. Modern society requires the manufacturing industry to respond quickly to market demand and produce products in small batches, multiple varieties, multiple specifications, low cost and high quality. In order to meet this requirement, the control systems of production equipment and automatic production lines must have extremely high performance. Reliability and flexibility, PLC programming appears in response to this requirement. It is a general-purpose industrial control device based on a microprocessor.

However, as customer needs change, there are more and more non-standard requirements, the proportion of non-standard equipment is getting larger and larger, and non-standard requirements are ever-changing. The traditional PLC programming method is difficult to maintain, has poor reusability, and is inconvenient to expand. The shortcomings of large non-standard changes necessitate a new program development method.

Contents of the invention

In view of the shortcomings of the existing technology, the present invention provides an object-oriented programming PLC standardized program development method, which is carried out according to the following steps:

1) Equipment analysis: analyze the structural configuration, control IO, valve sensors and their functions of the equipment, non-standard configuration and technology;

2) Electrical parameter table: The electrical parameter table is extracted from the equipment analysis, mainly including structural configuration, non-standard configuration, and process functions;

3) Underlying data: Plan the underlying data and structure the data;

4) Control objects: Extract all control objects from equipment analysis and electrical parameter tables, and use a module or an actuator as a control object. The hierarchical division of control objects is based on process needs. It is necessary to operate and control an actuator separately. Stand alone as a control object;

5) Object collection: use the object-oriented control method to write the attribute method programs of these control objects extracted in step 4) to form an object collection;

6) Process collection: Split the functions into independent and combinable process objects. Through association with control objects, the realization of each process function is satisfied, and finally a process collection is formed;

7) Variable process program: The customer's process is changeable or unclear. This variable process program associates the process with the process, allowing each step to independently select the process and set the process parameters independently. This method satisfies The need for flexible control;

8) Process execution: PLC program implements the work of each process;

9) State machine: Write a state machine program and meet the fault handling mechanism and device mode switching requirements.

Preferably, the underlying data in step 3) mainly includes system data, non-standard parameters, process data or parameters, command data/status, external data interaction, alarms and events, etc.

Compared with the prior art, the present invention has the following advantages:

According to the method provided by the invention, a set of PLC standardized programs can be compatible with one or more series of equipment, can add non-standard requirements to the program in a parameterized form, and expand the scope of equipment use. The standardized program written in an object-oriented programming manner, It has higher readability, good scalability, easy upgrades, and the application of variable process control strategies to achieve flexible control, products can be quickly switched, and the program can be parameterized, modularized, and standardized.

Description of the drawings

Figure 1 is a schematic diagram of the steps of the method of the present invention;

Figure 2 is a table of electrical parameters of the ebullated bed in the embodiment of the present invention.

Implementation

The present invention will be further described in detail below with reference to specific embodiments.

Example

An object-oriented programming PLC standardized program development method is carried out as follows:

1) Equipment analysis: analyze the structural configuration, control IO, valve sensors and their functions of the equipment, non-standard configuration and technology;

2) Electrical parameter table: The electrical parameter table is extracted from the equipment analysis, mainly including structural configuration, non-standard configuration, and process functions;

3) Underlying data: Plan the underlying data and structure the data. The underlying data mainly includes system data, non-standard parameters, process data or parameters, command data/status, external data interaction, alarms and events, etc.;

4) Control objects: Extract all control objects from equipment analysis and electrical parameter tables, and use a module or an actuator as a control object. The hierarchical division of control objects is based on process needs. It is necessary to operate and control an actuator separately. Stand alone as a control object;

5) Object collection: use the object-oriented control method to write the attribute method programs of these control objects extracted in step 4) to form an object collection;

6) Process collection: Split the functions into independent and combinable process objects. Through association with control objects, the realization of each process function is satisfied, and finally a process collection is formed;

7) Variable process program: The customer's process is changeable or unclear. This variable process program associates the process with the process, allowing each step to independently select the process and set the process parameters independently. This method satisfies The need for flexible control;

8) Process execution: PLC program implements the work of each process;

9) State machine: Write a state machine program and meet the fault handling mechanism and device mode switching requirements.

Taking the ebullating bed as an example, according to the method of the present invention and through equipment analysis, a common electrical parameter table for the ebullating dryer, the ebullating granulator, and the multifunctional vulcanized bed is extracted. After process analysis, it was found that these three types of equipment can use a set of object-oriented PLC standardized programs. Figure 2 shows the electrical parameter table of the ebullated bed. The table consists of three parts: customer data (order information), electrical parameters, and equipment technology. Through this table, we can know customer order demand information, non-standard requirements, and process requirements.

In terms of underlying data, the "system data" of the ebullated bed mainly includes system clock, IO table, PLC system data, calibration data, etc. The "non-standard parameters" are extracted from the electrical parameter table. The main non-standard parameters are: ebullated bed category, heating method, dehumidification method, etc.; "Process data or parameters" mainly include the inlet air temperature, material temperature, exhaust air temperature, left bag pressure difference, right bag pressure difference, bed pressure difference, high efficiency pressure difference, dust concentration, etc. ; "Instruction data/status" is mainly used to drive various process programs or interfaces to control object methods; "External data interaction" is mainly used for data interaction or control with third-party devices; "Alarms and events" are used for audit tracking , mainly including operation events, IO domain modification events, user management events, recipe management events, equipment alarms, etc.;

In terms of control objects, the ebullated bed is divided into structural modules according to five parts: air inlet, main body, exhaust, spraying, and cleaning. Among these five modules, the control objects can be divided according to actuators; for example, the air inlet can be Inlet air temperature control, inlet air humidity control, inlet air dew point control, inlet air volume control, initial, medium and high-efficiency pressure difference detection, etc.;

In terms of process collection, the ebullated bed can be divided into preheating, material preheating, granulation, coating, drying, cooling, feeding, discharging and other processes. These processes can also be used multiple times. For example, drying can be divided into drying 1. Drying 2, drying 3, etc. Granulation can also be divided into multiple stages. Parameters can be set independently for each process, and these parameters are independent of each other and do not interfere with each other.

In terms of variable process control, you can use PLC variable process control strategy or host computer control strategy to achieve variable process control. According to experience, the host computer variable process control is more flexible and has lower hardware requirements for PLC.

In terms of state machines, the standardized program has three working modes: manual, automatic, and debugging. The working status includes basic working statuses such as equipment ready, running, fault, stop, and cleaning. It also provides system status, such as communication status, etc.

In addition, a series of guidance documents have been developed for standardized procedures. These documents mainly include: PLC standardized program naming rules (mainly including the naming of variables, control objects, process names, state machines, etc.), program version control rules, equipment level hierarchical control methods, Control object attributes/method models and interface specifications, process splitting specifications and principles, non-standard parameter extraction methods and standards, variable process control strategies and specifications, third-party communication interface specifications, etc.

The above are only embodiments of the present invention. It should be noted that those of ordinary skill in the art can make various changes, modifications, replacements and modifications to these embodiments without departing from the technical principles of the present invention. Variations, these changes, modifications, replacements and modifications should also be regarded as the protection scope of the present invention.

Claims (2)

1. An object-oriented programming PLC standardized program development method, which is characterized by following the following steps: 1) Equipment analysis: analyze the structural configuration, control IO, valve sensors and their functions of the equipment, non-standard configuration and technology; 2) Electrical parameter table: The electrical parameter table is extracted from the equipment analysis, mainly including structural configuration, non-standard configuration, and process functions; 3) Underlying data: Plan the underlying data and structure the data; 4) Control objects: Extract all control objects from equipment analysis and electrical parameter tables, and use a module or an actuator as a control object. The hierarchical division of control objects is based on process needs. It is necessary to operate and control an actuator separately. Stand alone as a control object; 5) Object collection: use the object-oriented control method to write the attribute method programs of these control objects extracted in step 4) to form an object collection; 6) Process collection: Split the functions into independent and combinable process objects. Through association with control objects, the realization of each process function is satisfied, and finally a process collection is formed; 7) Variable process program: The customer's process is changeable or unclear. This variable process program associates the process with the process, allowing each step to independently select the process and set the process parameters independently. This method satisfies The need for flexible control; 8) Process execution: PLC program implements the work of each process; 9) State machine: Write a state machine program and meet the fault handling mechanism and device mode switching requirements. 2. An object-oriented programming PLC standardized program development method according to claim 1, characterized in that the underlying data in step 3) mainly includes system data, non-standard parameters, process data or parameters, and instruction data/ Status, external data interaction, alarms and events, etc.