Programmable Automation Programming of logical controllers Logical controllers
Programmable Automation Programming of logical controllers
Logical controllers' programming 1. 1 - Generalities All the Technicians, that they developed in the automation through cables, that is, I entrust the thread, they are today the first and big enthusiasts of this new technology computer science. In fact, those Professionals, a lot of times faced great obstacles, depressions and other problems for lack of functions or instructions that nowadays are within reach of any logical controller.
Logical controllers' programming 1. 1 - Generalities Many Technicians affirm, with conviction, that until it seems impossible the easiness with that it can project an automatic system now. Today, I control it of individualized machines or together, or still, the supervision and administration of a complete unit of production, have for base the programmable logical controller.
Logical controllers' programming 1. 1 - Generalities As tool comes to create a new philosophy before the old difficulties, because in the practice, that “black box” it executes all our requests or demands to the point of we could affirm that the scheduled automation only depends on the human imagination. This new instrument can be faced as a “block of notes” emptiness where we scored “everything” that very well understand that later on answers us in a logical way when we sent our requests or information.
Logical controllers' programming PLC 1. 2 - Concepts (PLC: programmable logic controller )
Logical controllers' programming 1. 2 - Concepts CONCEPT OF PLC The industrial programmable controller (PLC: programmable logic controller ) • It is an electronic equipment; • programmable in language non computer science; • conceived to control in real time and in industrial atmospheres, sequence processes.
Logical controllers' programming 1. 3 - Constitution In a simple way, we can consider the programmable logical controller as a device that processes information and whose constitution understands the following: ØCentral unit of Processing (CPU) ØModules of Entrances (Inputs) ØModules of Exits (Outputs) ØSpecial modules ØCommunication capacity
Logical controllers' programming 1. 3. 1 - CPU ØCentral unit of Processing (CPU) It is that the one that calls her–the controller's memory. üHabitually, its potentiality is it measured for the number of entrances and exits that it controls; üEven so, it is indispensable to analyze the maximum capacity of address of programs; üAscending and descending accountants; üTimers and bases of time; üAreas of special bits;
Logical controllers' programming 1. 3. 1 - CPU ØCentral unit of Processing (CPU) üand above all, the group of programming instructions, like for example: q Instructions of Transfer of Data q Instructions of Comparison q Arithmetic instructions in BCD (Binary coded decimal) q Basic instructions q Logical instructions q Special instructions
Logical controllers' programming 1. 3. 1 - CPU ØCentral unit of Processing (CPU) üAnother subject not less important it is the time that the controller needs, for to run every program. üThis depends on the number of instructions that they constitute the program and of the partial time of processing for each instruction. ü Usually, the logical controllers' makers indicate values among bad 30 and 0, 4 for 1 K of instructions (1 K = 1024 instructions). These are medium values, being destined 80% at basic instructions and 20% to processing of data
Logical controllers' programming 1. 3. 2 - Entrances ØModules of Entrances (Inputs) üThey are destined to the acquisition of arrived signs of the exterior. ü These can be binary or analogical and in the future they will be “fuzzy” (vacated or diffuse). üThe logic “fuzzy”, it was developed to turn the computers capable to flee to the binary logic traditional that just admits two logical values: False / true, black / white, zero / one.
Logical controllers' programming 1. 3. 2 -Entrances ØModules of Entrances (Inputs)
Logical controllers' programming 1. 3. 3 - Exits ØModules of Exits (Outputs) üThey drive the signs destined to the outputs after all the information internally to have been processed by the Central Unit. üThe digital modules can be the relay, transístor or triac üThe exits the relé is usually favorite because most of the time they release the joining relés to the actuadores.
Logical controllers' programming 1. 3. 3 - Exits ØModules of Exits (Outputs)
Logical controllers' programming 1. 3. 4 - Modules ØSpecial modules üThey are destined for example to the positioning of an or more axes in a motor step-to-step or to recognize signs of high frequency, as: vgenerators of pulses (encoders); vphotocells that generate signs whose period is of milliseconds and that difficultly can be seen in the normal considered entrances.
Logical controllers' programming 1. 3. 5 - Communication ØCommunication capacity üWith relationship to the communication, the common user can establish “dialogue “with the controller through one consoles, with appropriate keyboard or through a computer. üThe logical controllers, communicate with the computer by means of modules of “interface”, changing telegrams, whose content defines the area to reach, as well as the data that it receives or that sends.
Logical controllers' programming 1. 3. 5 - Communication ØCommunication capacity üThe capacity to communicate admits other levels, as the communication in net, where the logical controllers join through units of joining. üEven so, when the user communicates with the controller, he will have that doing through a language that it understands. üThere is, in fact, several programming languages as: Boollean, ladder Diagram , Functional or Logical, High level, and Grafcet.
Logical controllers' programming Summary In summary and in scheme form a logical controller is: POWER MEMORY SIGNS OF SENSOR E PROCESSOR CPU OUTLYING S SIGNS FOR RECEIVERS
Logical controllers' programming 1. 3. 6 -Peripherals peripherals
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