Controllers are essential devices for the efficient operation of machinery. How did they come about? Where are they applied? How does their installation, connection, configuration, repair and replacement of the controller look in general terms? The answers to these questions will be given within the framework of this article.
What are controllers?
This designation in automation systems is used for devices that are assigned the functions of controlling physical processes according to a previously recorded algorithm. In this case, information is used that comes from the sensors and is output to the actuators. In computers, controllers are devices that connect peripherals to internal data highways. Due to the processing of slow input / output operations, their functioning has a positive effect on the performance of systems. That is, controllers are devices that take over part of the functionality of the central processor. So, he no longer needs to constantly listen to whether the keyboard is active or not. The tasks of the central processor only include the readiness to receive data about the presence of interaction and respond accordingly.
History of occurrence
For the first time in the industry, they were used to build cars in the late 60s. They were used to automate assembly lines. Then computers were very expensive, so the controllers used hard logic, which was programmed in hardware. But their reconfiguration was a very time-consuming process. Therefore, devices arose that changed using a special relay. They got the name programmable logic controllers, and it has survived to this day. Over time, devices arose that were programmed in machine-oriented languages. This is easier to do constructively, but it is necessary to have a programmer to make even the smallest changes to the control algorithm. Since then, there has been a constant simplification of the task of the processes. First, high-level languages arose, and then special visual programming, which has a lot in common with ladder logic.
Application
You can find controllers almost everywhere: in the automation of technological processes, in machine tools with numerical control, in alarm and emergency protection systems, life support, building life support, security, communications, in medical and experimental equipment. Despite this proliferation, there are still enough areas where these devices are just beginning to appear.
Doing installation and replacement
How are controllers installed? For simplicity of explanation, and also taking into accounta large number of possible applications, we will consider a specific case with a device that deals with the temperature in the greenhouse. So, initially we will need to choose the installation horizon. As a rule, the middle of the height of adult vegetation is chosen as its quality. You need to take care of the place of attachment. It has certain requirements. So, it should be in a place where air circulation will be at least relatively carried out. In addition, there must be direct free access to the temperature sensor so that nothing interferes. Then the controller is directly installed, it is mounted in its place, and it remains to connect, configure and use its services. But what if there are problems with the hardware component of the device? If necessary, a replacement is carried out. You will have to disassemble the device and reassemble the entire temperature maintenance circuit, focusing on the physical characteristics of the new device.
Connecting
To power the controller, there are two main options:
- Stationary power source. This implies the presence of a battery that will supply energy to the controller. The advantages of this option include a significant level of autonomy. But the battery of the controller in this case should be charged regularly. You can automate this process by designing a circuit that will connect it to the network. When the charge is less than a certain value (say, 50%), it will turn onmake-up. But this is an additional waste of energy (albeit not very significant).
- Power grid. This implies the connection of the controller to the power grid. But if you need to constantly control the temperature (in a greenhouse with exotic plants or a chicken incubator), then because of the possibility of power loss, this option is not suitable. We need to weigh the pros and cons of each scheme.
Customize
It's pretty simple here. The controller simply needs to be configured for the required temperature range and actions when it passes. If we talk about a purchased device, then it should be provided with interfaces, by working with which you can do everything you need. With homemade devices it will be a little more difficult. You can select the required temperature regime in the greenhouse by adding new elements or changing the values \u200b\u200bof already installed ones. In this case, care should be taken not to accidentally burn the circuit due to overload or not to put a part that will make it insensitive. To do this, it will be necessary to make the appropriate calculations and make sure that they are correct in practice. That's the whole controller setup.
Repair
When controllers fail, there are three main options:
- Give it to the professionals to fix it.
- Throw it away and buy a new one.
- Repair yourself.
Each of them is expensive in its own way. So, the first two rest mostly on money, and the third on their own time and effort. And if out ofbuilding a factory controller, then it’s better not to try to figure it out on your own (although in the end it all depends on the desires and confidence in one’s own skills). Repair yourself is best suited in cases where the device was personally assembled and assembled. In this case, it will be necessary to use special equipment (or test circuits) and establish the performance of each element. And when a non-working link is identified, it will need to be unsoldered, and in its place a new part should be installed that has no problems with functioning. That's the whole repair of the controller with your own hands. For the master, this is nothing difficult.
Conclusion
As you can see, controllers are not difficult. The same can be said about the processes of working with them. But it must be remembered that controllers are devices that operate under a certain voltage, so you should be careful. The best option would be to place the device in a shell, due to which access to it by unauthorized persons will be significantly limited.
