Programmable controller programming language:
There are a variety of programming languages in the programmable controller, which are ladder language, Boolean, functional graph, functional block diagram language, and structural language description language. The ladder language and the Boolean logo language are the basic programming language, which is usually constructed of a series of instructions, with these instructions can complete most simple control functions, for example, instead of relay, counters, timer completion sequential control and logic control Wait, by expanding or enhanced instruction sets, they can also perform other basic operations. Functional Photo Language and Statement Description Languages are advanced programming languages, which can perform more efficient operations as needed, for example, analog control, data manipulation, report prints, and other basic programming languages cannot be completed. Features. The functional block diagram language uses the form of functional block diagram, completes the required control functions by soft connection, not only has a wide range of applications in the editing controller, but also often in the programming and configuration of the distribution control system. It is used, because it has convenient connection, simple operation, easy to master, and loves the majority of engineering design and application staff.
According to the programmable application range, the programming language can be used in combination, and the commonly used programming language is:
Ladder programming language
Boolean support logger design language (statement table)
Functional Photo Program Design Language
Function module graph programming language
Structured statement description programming language
Ladder and structured statement description programming language
Boolean Assistance and Function Photo Program Design Language
Boolean Assistance and Structured Graphical Description Program Design Language
1, ladder diagram (ladder diagram) programming language
The ladder programming language is a programming language of the program with a graphic symbol of a ladder chart. Using a ladder programming language, the program is described in the form of a ladder diagram. This programming language uses causal relationships to describe the conditions and results of the event. Each level is a causal relationship. In the step, the condition that the event occurs is represented on the left, the result of the event generation is represented behind.
Ladder programming language is the most common programming language. It comes from a description of the relay logic control system. In the field of industrial process control, electrical technicians are familiar with relay logic control technology, and therefore, the trapezoidal maps from this logic control technology have been welcomed and have been widely used.
Ladder programming language features:
(1) It corresponds to the electrical operation schematic, which is intuitive and corresponding;
(2) Also consistent with the original relay logic control technology, for electrical and technical personnel, easy to take and learn;
(3) The difference between the original relay logic control technology is that the power flow in the trapezoidal is not the actual current, and the internal relays are not actually existing relays. Therefore, when applied, it is necessary to Relevant concepts of relay logic control technology;
(4) There is a one-one correspondence with the Boolean logger design language, which is easy to transition and program check.
2, Boolean Mnemonic programming language
The Boolean support logging programming language is a programming language of the program with a Boolean helper. The Boolean support logging programming language is very similar to assembly language in the computer, using a Boolean help message to represent operational functions.
The Boolean Assist Application Language has the following features:
(1) Use a mission to represent the operation function, which is easy to remember, and it is easy to hold;
(2) In the keyboard of the programmer, a mission is represented, and the characteristics of easy operation can be programmed in an instant computer; (3) There is a one-one correspondence with the trapezoidal view. It features the basic class of the ladder pattern.
3, functional table (Sepuential Function Chart) programming language
Functional Photo Graph Programming Language is a programming language for programming programs with a functional graph. It is a programming language that has developed in recent years. With the description of the functional graph, the control system is divided into several subsystems, starting from the function, making the system's operations with a clear meaning, facilitating the communication of designers and operators design ideas, facilitating the design and inspection and commissioning of procedures. Function The characteristics of the programming language are:
(1) It is clear to function as the main line, and it is easy to understand and communicate with the program operation;
(2) For large procedures, division of labor, which uses more flexible programming, saving program design time and debugging time;
(3) Operations commonly used in the scale of the system, the procedure relationship is more complicated;
(4) Only the command and operation of the active step are executed, and the conversion after the active step is scanned, so the scan time of the entire program is greatly shortened than the program scan time prepared by other programs.
The functional table is derived from the Petri network. Since it has graphical expression, it can describe all the phenomena of concurrent systems and complex systems, and can be unsafe to the system in the system. Anomalous phenomenon is analyzed and modeled, and can be programmed directly on the basis of the model, so it has been applied. Software for programming language using functional graph description languages in recent years has also been provided. About some of the basic concepts of Petri.com, I will introduce you when I have the opportunity to help further understand the functional graph.
4, function block diagram (Function Block) programming language
Functional Module Programming Language is a functional module to represent the functionality of the module, and different functional modules have different functions. It has several inputs and outputs, which are connected to the desired other terminals, complete the desired control operation or control functionality, respectively. Functional modules can be divided into different types, in the same type, may also be different due to the difference in functional parameters, for example, the number of inputs, the type of input signal, etc., etc. different. Since the function module is used in a soft connection, the function module is connected to the external terminal, so the operation of the control scheme, the replacement of the signal connection can be conveniently implemented. Functional Module Programming language features:
(1) It is easy to start from the control function, enabling the analysis and understanding of the control scheme to make the control function;
(2) The functional module is a graphical method description function, which greatly facilitates the programming and configuration of designers, and has better operatory operations;
(3) System for the control scale and control relationship, due to the relationship between control functions, the programming and configuration time can be shortened, and the debug time can be reduced;
(4) Since each function module needs to occupy a certain program memory, the implementation time of the function module needs to be executed, so this design language is only in the programming and configuration of large and medium-sized programmable controllers and distribution control systems. Adopted. 5. Structured Schemration (Structured Text) Description Program Design Language
Structured statements Description programming language is a programming language for describing the program with a structured description statement. It is a programming language similar to advanced languages. In a large and medium-sized programmable controller system, a structured statement description programming language is often used to describe the relationship between the various variables in the control system. It is also used for programming and configuration of the distribution control system.
The structured statement description programming language uses a computer's description statement to describe various arithmetic relationships between various variables in the system, complete the desired function or operation. Most manufacturers use the statement description programming language similar to advanced languages such as Basic language, PASCAL languages, or C language, but for application convenience, simplification of statements and the species of statements.
Structured programming language has the following features:
(1) Programming with advanced languages, can complete more complex control operations;
(2) There is a need for a certain knowledge and programming skill of computer advanced programming language, and the skills of programmers have higher requirements, and ordinary electrical personnel cannot be completed.
(3) Performance and easy operability and other performance;
(4) Implementation of some control functions that are often used in other languages such as functional modules.
Partial programmable controller manufacturing vendors provide users with simple structured programming language, which is similar to that of the macrper design language, has certain restrictions on the number of procedures, while providing programs control The interface between the interface or the communication connection program between the device provides an extension for the user's application.
