Synthesis of circuits on logical elements according to specified conditions
Digital electronic circuits based on logic elements are used as control circuits for a wide variety of control and regulation of technological objects. Under the synthesis of the circuit understand its design (development).
Before starting the synthesis of the circuit, the task that the circuit should solve should be clearly and unambiguously formulated. Verbal language can often be interpreted ambiguously. Therefore, the technical task for the development of the scheme requires special attention.
First of all, you need to assign input variables. Uppercase letters of the alphabet are used as characters, starting with the first, with or without an index.
Input variables, for example: A, B, C, D, E, F, G, £, E2, E3.
Then assign the output variables. As characters for the output signals, capital letters of the alphabet are used, starting with the last:
Output variables, for example: Z, Y, X, Vv Ug, V3.
Then it is necessary to stipulate under what conditions the variables are 1 and 0.
After this, you can begin to compile a truth table. It will immediately become clear whether the verbal description was unambiguous. If ambiguity occurs during the compilation of the table, it must be immediately eliminated by discussion with other developers and customers.
The truth table uniquely determines how the designed circuit will work.
After building the truth table, logical elements are selected on which it can be implemented. The scheme should be as simple as possible and consist of elements available.
You should try to simplify the found scheme as much as possible. If, for example, only AND-NOT elements are available, the circuit must be transformed so that it consists only of AND-NOT elements.
So, for the synthesis of the circuit, five steps can be distinguished:
1. Description of the function of the required circuit.
2. Assignment of input and output variables and assignment of values \u200b\u200b0 and 1.
3. Compilation of truth tables.
4. Determination of the necessary logical operations.
5. Simplification and, if necessary, transformation of the circuit. Let's consider this step-by-step synthesis on a concrete example.
Example
It is necessary to synthesize a circuit that prevents the elevator from starting under certain conditions.
Step 1. Description of the function of the required circuit
The elevator cannot move when the door is open. It also cannot get under load. To start, press the button.
Step 2. Assigning input and output variables
Input variable A is assigned to the door contact. A \u003d 1 means that the door contact is closed, A \u003d O means that the door contact is open.
The input variable B is assigned for overload (B \u003d 1: overload, B \u003d 0: no overload).
The input variable C is assigned to the button (C \u003d 1: the button is pressed, C \u003d 0: not pressed).
The output variable will be Z.Z— 1 means that the elevator can go. Z \u003d 0 means that the elevator cannot go.
Step 3. Creating a truth table
We have three variables. Therefore, the truth table has 8 possible options (Fig. 5.1). The elevator can go when the door is closed (A \u003d 1), there is no overload (B \u003d 0) and the button is pressed (C \u003d 1).
All these conditions are fulfilled simultaneously only in version 6 of the truth table (Fig. 5.1). For this option, Z \u003d 1. In all other cases, Z \u003d 0.
Step 4. Determining the necessary logical operations
After compiling the truth table, you can calculate the scheme. Calculation rules will be given later. For such a simple task, the selection method can also be applied.
Z is equal to 1 only when A \u003d 1, 5 \u003d 0 and C \u003d 1. If you apply input B to the inverter NOT, then the output of this element will be state 1. When A \u003d 1,
B \u003d 1 and C \u003d 1, we have three 1-states. They then go to the input of the three-input element And (Fig. 5.2).
At the output of the element And only 1 acts when L \u003d 1, 5 \u003d 0 and C \u003d 1. This output is a Z-output. In fig. 5.2 shows the required safety circuit. Z \u003d 1 means, for example, that +5 V is applied to the output Z. This voltage can switch the elevator start relay.
The method of finding the circuit by the selection method can be described as
The ability to choose a variant of the circuit that performs the required logical operations of multiplying or adding the input variables and their inverted values.
Step 5. Simplify and, if necessary, transform the circuit
The circuit in fig. 5.2 cannot be simplified. However, it can be transformed. Suppose we have only OR-NOT elements at hand. Then the function Z \u003d A l B l C can be transformed:
Z \u003d AaBaC \u003d AaBaC \u003d AvBvC.
The circuit, built on the elements of OR NOT, is shown in Fig. 5.3.
Fig. 5.3. Co elevator safety circuit. on items OR NOT
As a result of the development of chapter 9, the student must:
know
- the nature of the decision-making process;
- factors affecting the management decision-making process;
be able to
- formulate and diagnose the problem, identify alternatives to its solution and give them an assessment;
- apply the modern scientific methodology of research and solving specific management problems;
own
Methods of preparation and implementation of management decisions, collection, processing and analysis of information on individual management problems.
Logic and control logic
Control logic is a system of targeted actions that are carried out in a strictly defined sequence over a specified period of time.
Control logic can be represented in the form of a diagram, the most important elements of which are: foresight, decision, programming, execution, control and analysis.
Foresight is the starting point in the control logic, because to manage is to foresee.
“Indeed,” A. Fayol wrote in his paper “General and Industrial Management,” “if foresight is not one hundred percent management, then in any case it is an essential part of the latter. Foreseeing here means calculating the future and preparing it. Foreseeing is almost action. ”
Foresight involves a solution. Decision - this is an alternative choice. At the same time, a solution is a product of managerial work that increases or decreases the efficiency of a commercial enterprise (organization).
Programming is, first of all, the choice of means and the development of an action program. The action program is based on the resources of the enterprise, i.e. in accordance with the established goal, it is necessary to clearly present the desired situation and the stages of its achievement, as well as to link tasks at each stage with the resources of the enterprise. In other words, it is necessary to determine the necessary availability of real estate, equipment, raw materials, money capital and other means necessary both for the achievement of the ultimate goal, and for the successful implementation of each stage of its achievement.
The success of programming largely depends on the correct determination of the stages of achieving goals, on the rational distribution of tasks between departments, services of the managed system, as well as on the interest of each department in the implementation of both individual stages and the program as a whole.
The next link in the control logic is execution. Execution - it is a system of specific actions aimed at implementing the program. For the successful implementation of the program as a whole, it is necessary, along with highlighting the stages of its implementation, to establish tasks for each unit participating in the implementation of the program. At the same time, the tasks of general and private programs should be interconnected by tasks, priorities, resources, volume and deadline. The necessary conditions for the implementation of any program are unity, continuity, flexibility and accuracy. During the execution of the program there is a need to stimulate participants in its implementation.
In order to minimize the number of unforeseen deviations from the tasks of the program during its execution, control is necessary. The control, or verification of performance, is a necessary function and the most important link in the control logic. Control should be systematic, integrated, effective, vowel. The purpose of control is to identify deviations from program tasks or errors in its implementation and eliminate them. To do this, monitoring should be carried out not occasionally, but constantly, not according to individual tasks or indicators, but to the whole complex of program settings. Verification of the tasks should not only identify deficiencies in the implementation of the tasks of the program, but also quickly eliminate them. And finally, disruptions in program implementation should not be hushed up; on the contrary, they should be actively overcome with the implementation, if necessary, of mobilizing additional resources of the management system. Performance monitoring results should be carefully analyzed.
Analysis involves dividing the whole into parts, studying these parts and their relationships, identifying the most important parts or elements that determine the state of the system as a whole, preparing conclusions and recommendations but improving the functioning of the management system.
The most important result of the analysis of the implementation of the organization’s activity program is either the preparation of proposals for adjusting the program in accordance with changes in the environment or management system, or, if foresight has not justified itself, refusal to foresee. Graphically, the logical control circuit is shown in Fig. 9.1.
Fig. 9.1.
The logic diagram determines the control technology. Management technology It is a system of operations and procedures performed by managers.
Management technology should ensure the implementation of the program-targeted approach in management.
The goal is the mental anticipation of performance. With regard to management, the goal can be represented as the desired state of the control object after a certain period of time. In order for the control system to move from a predetermined state to a desired one, a certain program of actions is needed that would allow overcoming the problems separating a given situation from the desired situation. The strategic goals of the organization are determined based on its mission. The choice of tactical goals involves the implementation of a number of operations and procedures according to the management decision-making scheme. The choice of goal, which has taken the form of a final decision, allows you to move on to developing a program, i.e. to carry out operations and procedures, to develop a detailed plan of action and to determine the resources necessary to achieve the goal. At this stage, balance calculations are made, norms and standards are widely used, analytical work is carried out.
After the target program is defined, its implementation begins. As the target program is implemented, its execution is monitored in terms of volume, resources and timing. It is dominated by management operations and procedures related to verification of performance. Monitoring should be systematic, comprehensive and effective, and the verification data for the implementation of the target program should be carefully analyzed.
Analytical operations and procedures allow you to compare goals and results achieved at each stage of the program. The implementation of analytical operations and procedures is necessary due to the fact that during the implementation of the program there are often changes in the management system and in its environment, which were absent or were not taken into account at the time of the formation of the program itself. In order to adequately respond to these changes, according to the results of the analysis, operations and procedures related to the adjustment of the program can be performed.
There are a number of general requirements for management objectives. Goals must be concrete, measurable and achievable. They must be interconnected, i.e. the operations and procedures necessary to achieve one goal should not interfere with the achievement of other goals of the organization.
In addition, goals are coordinated in time. Classification of goals by time implies a forecast horizon. Based on this, long-term, short-term and medium-term goals and their corresponding programs are distinguished. Long-term target programs have a planning horizon of 5–10 years, medium-term ones are implemented in 3-5 years, and short-term ones, as a rule, are implemented during the year.
Goals usually determine the main areas of work of the organization. For this work to be carried out successfully, it is necessary to divide the goal into stages of achievement (sub-goals) and clearly define quantitatively measurable boundaries at each stage. Moreover, in order for the goal itself and all its stages to be completed in full and on time, it is necessary to carry out a set of management operations and procedures aimed at ensuring complete coordination of the tasks and resources.
The target program usually contains a specific set of sections and indicators that contain data on the goal and stages of its achievement, on the material resources and financial resources necessary for its implementation, on capacities and investments, as well as on the labor resources involved in fulfilling the tasks of the program. The tasks of the program are distributed among its executors. Moreover, the actions of the latter are strictly coordinated, and each contractor is responsible for the implementation of its part of the program.
Target programs are classified according to various criteria:
- - by management level (distinguish between national programs implemented at the macro level, regional programs implemented within certain territories, and programs implemented at the micro level, i.e. at the enterprise level);
- - on the object of management (allocated economic, environmental, social, political and other programs);
by terms of implementation (long-term, medium-term, short-term), etc.
The most important aspect of management technology is the process of preparing, making and implementing management decisions.
Self Test Questions
1. What is the essence of the concept of "management methods"?
2. How are management practices classified?
3. What are the main tools of state regulation of the economy?
4. What are the main features of internal planning?
5. What methods of financial management are widely used at the enterprise level?
6. What is the essence of commercial calculation?
7. Why is it necessary to use organizational and administrative methods of management?
8. What are the most common methods of organizational impact in management?
9. What methods of administrative influence are used in management?
10. For the solution of what tasks are used socio-psychological management methods?
11. What socio-psychological methods have been widely used in management?
12. What are the methods of moral incentives?
Chapter 9. Management Solutions
9.1. Logic and control logic
Control logic is a system of targeted actions that are carried out in a strictly defined sequence over a specified period of time.
Control logic can be represented in the form of a diagram, the most important elements of which are: foresight, decision, programming, execution, control and analysis.
Foresight -this is the starting point in the logical control scheme, because to manage is to foresee.
“Indeed,” A. Fayol wrote in his work “General and Industrial Management,” “if foresight is not one hundred percent management, then in any case it is an essential part of the latter. Foreseeing here means calculating the future and preparing it. Foreseeing is almost action. ”
Foresight involves a solution.
Decision -it is a choice of purpose. At the same time, a solution is a product of managerial work, which, ultimately, increases or decreases the efficiency of an organization. Making a decision involves determining the target setting, which ultimately determines the prospects for the development of the control object, the choice of means to achieve the goal, and the development of an action program.
Programming -this is, first of all, the choice of means and the development of an action program. The action program is based on the resources of the enterprise, i.e. in accordance with the established goal, it is necessary to clearly present the desired situation and the stages of its achievement, as well as to link tasks at each stage with the resources of the enterprise. In other words, to determine the necessary availability of real estate, equipment, raw materials, cash capital and other means necessary both for the achievement of the ultimate goal, and for the successful implementation of each stage of its achievement.
An important tool for linking goals and resources at the organization level is the provisional budgets of enterprises.
The success of programming largely depends on the correct determination of the stages of achieving goals, on the rational distribution of tasks between departments, services of the managed system, as well as on the interest of each department in the implementation of both individual stages and the program as a whole.
The next link in the control logic is execution. Execution -it is a system of specific actions aimed at implementing the program. For the successful implementation of the program as a whole, it is necessary, along with highlighting the stages of its implementation, to establish tasks for each unit participating in the implementation of the program. At the same time, the tasks of general and private programs should be interconnected by tasks, priorities, resources, volume and deadline. The necessary conditions for the implementation of any program are unity, continuity, flexibility and accuracy. During the execution of the program there is a need to stimulate participants in its implementation.
In order to minimize the number of unforeseen deviations from the tasks of the program during its execution, control is necessary.
The control,or verification of performance, is the necessary control function and the most important link in the control logic. Control should be systematic, integrated, effective, vowel. The purpose of control is to identify deviations from program tasks or errors in its implementation and eliminate them. To do this, monitoring should be carried out not occasionally, but constantly, not according to individual tasks or indicators, but over the entire range of program settings. Verification of assignments should not only identify deficiencies in the implementation of the tasks of the program, but also promptly eliminate them. And finally, failures in the implementation of the program should not be silent; on the contrary, they should be actively overcome with the implementation, if necessary, of mobilizing additional resources of the management system. Performance monitoring results should be carefully analyzed.
Analysisinvolves dividing the whole into parts, studying these parts and their relationships, identifying the most important parts or elements that determine the state of the system as a whole, preparing conclusions and recommendations for improving the functioning of the management system.
With regard to the analysis of the implementation of the organization’s program of activities, the most important result is either the preparation of proposals for adjusting the program in accordance with changes in the environment or management system, or, if foresight has not justified itself, the rejection of foresight. Graphically, the control logic is shown in Fig. 9.1.
Fig. 9.1. Control logic
The logic diagram determines the control technology.
Management technology is a system of operations and procedures performed by managers.
Management technology should ensure the implementation of the program-targeted approach in management. The goal is the mental anticipation of performance. With regard to management, the goal can be represented as the desired state of the control object after a certain period of time. In order for the control system to move from a predetermined state to a desired one, a certain program of actions is needed that would allow overcoming the problems separating a given situation from the desired situation. The strategic goals of the organization are determined based on its mission. The choice of tactical goals involves the implementation of a number of operations and procedures according to the scheme of managerial decision making. Choosing a target that has taken the form of a final decision allows you to proceed to the development of the program, i.e. to carry out operations and procedures, to develop a detailed plan of action and to determine the resources necessary to achieve the goal. At this stage, balance calculations are made, norms and standards are widely used, analytical work is carried out.
After the target program is defined, its implementation begins. As the target program is implemented, its execution is monitored in terms of volume, resources and timing. It is dominated by management operations and procedures related to verification of performance. Monitoring should be systematic, comprehensive and effective, and the verification data for the implementation of the target program should be carefully analyzed.
Analytical operations and procedures allow you to compare goals and results achieved at each stage of the program. The implementation of analytical operations and procedures is necessary due to the fact that during the implementation of the program there are often changes in the management system and in its environment, which were absent or were not taken into account at the time of the formation of the program itself. In order to adequately respond to these changes, according to the results of the analysis, operations and procedures related to the adjustment of the program can be performed.
There are a number of general requirements for management objectives. Goals must be concrete, measurable and achievable. They must be interconnected, i.e. the operations and procedures necessary to achieve one goal should not interfere with the achievement of other goals of the organization.
In addition, goals are coordinated in time. Classification of goals by time implies a forecast horizon. Based on this, long-term, short-term and medium-term goals and their corresponding programs are distinguished. Long-term target programs have a planning horizon of 5–10 years, medium-term ones are implemented in 3-5 years, and short-term ones, as a rule, are implemented during the year.
Goals usually determine the main areas of work of the organization. For this work to be carried out successfully, it is necessary to divide the goal into the stages of its achievement (sub-goals) and clearly define quantitatively measurable boundaries at each stage. At the same time, in order for the goal itself and all its stages to be completed in full and on time, it is necessary to carry out a set of management operations and procedures aimed at ensuring complete coordination of the tasks and resources.
The target program usually contains a specific set of sections and indicators that contain data on the goal and stages of its achievement, on the material resources and financial resources necessary for its implementation, on capacities and investments, as well as on the labor resources involved in fulfilling the tasks of the program. The tasks of the program are distributed among its executors. Moreover, the actions of the latter are strictly coordinated, and each contractor is responsible for the implementation of its part of the program.
Target programs are classified according to various criteria: by level of management (they distinguish between national programs implemented at the macro level, regional programs implemented within certain territories, and programs implemented at the micro level, i.e., at the enterprise level); on the object of management (economic, environmental, social, political and other programs are highlighted); by terms of implementation (long-term, medium-term, short-term), etc.
The most important aspect of management technology is the process of preparing, making and implementing management decisions.
| " |
Control logic is a system of targeted actions carried out in a strictly defined sequence over a specified period of time.
Control logic can be represented in the form of a diagram, the most important elements of which are: foresight, decision, programming, execution, control and analysis.
Foresight is the starting point in the control logic, because to manage is to foresee.
“Indeed,” A. Fayol wrote in “General and Industrial Management,” Innovation Management: A Training Manual / Goldstein G.Ya. Taganrog: TRTU Publishing House, 2010. 132p., - if foresight is not a hundred percent management, in any case, it is an essential part of the latter. To foresee here means to calculate the future and prepare it. To foresee is almost to act.
Foresight involves a solution.
The solution is the choice of purpose. At the same time, a solution is a product of managerial work, which ultimately increases or decreases the effectiveness of the organization. Making a decision involves determining the target setting, which ultimately determines the prospects for the development of the control object, the choice of means to achieve the goal and the development of an action program.
Programming is, first and foremost, the choice of tools and the development of an action program. The action program is based on the resources of the enterprise, i.e. in accordance with the established goal, it is necessary to clearly present the desired situation and the stages of its achievement, as well as to link tasks at each stage with the resources of the enterprise. In other words, to determine the necessary availability of real estate, equipment, raw materials, money capital and other means necessary both for the realization of the ultimate goal, and for the successful implementation of each stage of its achievement.
An important tool for linking goals and resources at the organization level is the provisional budgets of enterprises.
The success of programming largely depends on the correct determination of the stages of achieving goals, on the rational distribution of tasks between departments, services of the managed system, as well as on the interest of each department in the implementation of both individual stages and the program as a whole.
The next link in the control logic is execution.
Execution is a system of specific actions aimed at implementing a program. For the successful implementation of the program as a whole, it is necessary, along with the identification of the stages of its implementation, to establish private programs (or plans) of work for each unit involved in the implementation of the program. At the same time, the tasks of general and private programs should be interconnected according to tasks, priorities, resources, volume and deadline. The necessary conditions for the implementation of any program are unity, continuity, flexibility and accuracy. In the course of program execution, usually a number of problems arise, associated, on the one hand, with the motivation of participants in the implementation of the program, and on the other with environmental changes, since foresight is not a prophecy, and the environment cannot remain unchanged for a long time.
In order to minimize the number of unforeseen deviations from the tasks of the program during its execution, control is necessary.
Monitoring, or verification of performance, is a necessary control function and the most important link in the control logic. Control should be systematic, integrated, effective, vowel. The purpose of control is to identify deviations from program tasks or errors in its implementation and eliminate them. To do this, monitoring should be carried out not occasionally, but constantly, not according to individual tasks or indicators, but over the entire range of program settings. Verification of the tasks should not only identify deficiencies in the implementation of the tasks of the program, but also quickly eliminate them. And finally, failures in the implementation of the program should not be silent; on the contrary, they should be actively overcome with the implementation, if necessary, of mobilizing additional resources of the management system. Performance monitoring results should be carefully analyzed.
Analysis involves dividing the whole into parts, studying these parts and their relationships, identifying the most important parts or elements that determine the state of the system as a whole, preparing conclusions and recommendations for improving the functioning of the management system.
With regard to the analysis of the implementation of the organization’s program of activities, the most important result is either the preparation of proposals for adjusting the program in accordance with changes in the environment or management system, or, if foresight has not justified itself, the rejection of foresight. Graphically, the control logic is presented in the application.
The logic diagram determines the control technology. Kolesnik M. Management. M .: "Publishing house PRIOR”, 2008. 345 p.
Management technology is a system of operations and procedures performed by managers. Moreover, the concepts of “operation” and “procedure” in management are not identical.
Management technology should ensure the implementation of the program-targeted approach in management. The goal is the mental anticipation of performance. With regard to management, the goal can be represented as the desired state of the control object after a certain period of time. In order for the control system to move from a predetermined state to a desired one, a certain program of actions is needed that would allow overcoming the problems separating a given situation from the desired one. The strategic goals of the organization are determined based on its mission. The choice of tactical goals involves the implementation of a number of operations and procedures according to the management decision-making scheme. The choice of goal, which has taken the form of a final decision, allows you to move on to developing a program, i.e. to carry out operations and procedures, to develop a detailed plan of action and to determine the resources necessary to achieve the goal. At this stage, balance calculations are made, norms and standards are widely used, analytical work is carried out.
After the target program is defined, its implementation begins. As the target program is implemented, its execution is monitored in terms of volume, resources and terms. It is dominated by management operations and procedures related to verification of performance. Monitoring should be systematic, comprehensive and effective, and the verification data for the implementation of the target program should be carefully analyzed.
Analytical operations and procedures allow you to compare goals and results achieved at each stage of the program. The implementation of analytical operations and procedures is necessary due to the fact that during the implementation of the program, changes often occur in the management system and in its environment, which were absent or were not taken into account at the time of the formation of the program itself. In order to adequately respond to these changes, according to the results of the analysis, operations and procedures related to the adjustment of the program can be performed.
There are a number of general requirements for management objectives. Goals must be concrete, measurable and achievable. They must be interconnected, i.e. the operations and procedures necessary to achieve one goal should not interfere with the achievement of other goals of the organization.
In addition, goals are coordinated in time. Classification of goals by time implies a forecast horizon. Based on this, long-term, short-term and medium-term goals and their corresponding programs are distinguished. Long-term target programs have a planning horizon of 5–10 years, medium-term ones are implemented in 3-5 years, and short-term ones, as a rule, are implemented during the year.
Goals usually determine the main areas of work of the organization. For this work to be carried out successfully, it is necessary to divide the goal into the stages of its achievement (sub-goals) and clearly define quantitatively measurable boundaries at each stage. At the same time, in order for the goal itself and all its stages to be completed in full and on time, it is necessary to carry out a set of managerial operations and procedures aimed at ensuring complete coordination of the tasks and resources.
The target program usually contains a specific set of sections and indicators that contain data on the goal and stages of its achievement, on the material resources and financial resources necessary for its implementation, on capacities and investments, as well as on the labor resources involved in the implementation of a given program. The tasks of the program are distributed among its executors. Moreover, the actions of the latter are strictly coordinated, and each contractor is responsible for the implementation of its part of the program.
Target programs are classified according to various criteria: by the level of management (they distinguish between national programs implemented at the macro level, regional programs implemented within certain territories, and programs implemented at the micro level, i.e. at the enterprise level); on the object of management (economic, environmental, social, political and other programs are highlighted); by terms of implementation (long-term, medium-term, short-term), etc.
Management technology is based on an information base. This raises the problem of processing a significant amount of information in a short time. To successfully solve this problem, modern technical support of the management process is necessary.
Relay-contactor control systems
Under the term RCSU (Relay-contactor control systems) understand logical control systems built on a relay-contactor element base and automating the operation of the drive.
To the task of RCSU includes automation of the following processes:
turning on and off the engines,
selection of direction and speed of rotation,
engine starting and braking,
creating temporary pauses in motion,
protective shutdown of the engine and stop of the mechanism.
The direct control object for the RCSU is a mains powered engine.
To the advantages of RCSU applies: the presence of galvanic isolation of circuits, significant switching power, high noise immunity.
Disadvantages of RCSU are: contact switching, requiring appropriate maintenance and limiting its service life; limited performance; increased overall dimensions and power consumption.
Electrical circuits and methods of analysis of RCSU
The sequence of operation of the nodes in the RKSU depends on their electrical connections.
The electrical circuit of the RCSU is a graphic form of the image of the RCSU.
Figure 2.2 shows the general functional diagram of the RKSU in the form of nodes.
IN concept all elements of the control system, electrical connections of the elements are given. An image of a node is allowed without disclosing its internal content. If the node is not standard, then its circuit should be additionally given as an application. The scheme does not give a spatial arrangement of the equipment, therefore, an additional installation diagram is given.
You can evaluate the performance and quality of the developed RCSU based on its analysis.
In the general analysis, the characteristic of the RCCU is given in general, the purpose of the system, the type of element base are indicated, the main nodes are highlighted and the principles on which they are built are highlighted. The description method is verbal.
A detailed analysis provides a detailed description of the functioning of the entire DCSU or its individual nodes, describes the algorithm of the logical control system.
The algorithm can be represented both verbally and formally - symbolically, analytically and graphically.
The most rigorous and compact formalization of the description of the RKSU is a nalitichesky way expressed in structural formulas of Boolean algebra of logic. Denoting the logical input independent variables by, the internal dependent variables by, and the output variables (functions) by, we obtain structural formulas of a similar type:
Such a record does not reflect the time sequence of the operation of this node. This method is used mainly in the synthesis of RKSU, in the formation of an analytical control algorithm.
For a detailed analysis of the RCCU, a graphical description method is used in the form of a graph or cyclogram.
The cyclogram consists of the following elements:
tact - time interval at which no changes occur in the state of the system;
power-on period - the time interval of the on state of the device (shown by a horizontal line in a row);
shutdown period - the time interval of the disconnected state of the device (depicted by the absence of a horizontal line);
the impact of one device on another is depicted by a thin vertical line.
All cycles and periods of switching on and off are displayed on the cyclogram without observing the quantitative time scale. The logical time scale can be considered a measure.
Fig. 3.2. Cyclogram of the anti-inclusion braking unit
Example: cyclogram of the anti-inclusion braking unit. The initial initial state of the system is the rotation of the engine in the "forward" direction at full speed (right third position Sm1 ), for the end of the cyclogram - the start of the launch in the "back" direction. In this node, signals of the command controller for output variables are accepted as input independent variables - functions - contactor currents KM1 - KM7, and for the internal variable - rotor voltage relay current Kv . The cyclogram will have the form shown in Fig. 3.2. It has seven measures, 2 - 5 and 7 are unstable. - disconnecting measure; - enabling measures.
