Programmable logic controller – without this device, it is impossible to imagine the operation of today's production, process or transport lines. This technology has brought a new dimension of innovation to industry. What is a programmable logic controller? How do you choose the right controller for your application? In this blog post, we answer these and many other questions based on our programmable controllers JUMO variTRON 300 and JUMO variTRON 500. Check it out!
A PLC (Programmable Logic Controller) is a type of small industrial computer that receives data via inputs and sends instructions via outputs. The device makes decisions based on the logic functions and controls system functions proggramed in PLC system. Programmable logic controllers are used in all industries to automate critical industrial processes and control the operation of machines.
PLC controller with modules JUMO variTRON 500
A PLC takes input data (e.g. sensor signals). Then an appropriately programmed microprocessor, analyses this information in a cyclic manner. The controller verifies these commands in the order in which they were written in the programme and then creates a so-called output image. The outputs of a PLC can control a wide variety of devices, including motors, solenoid valves, lighting, switchgear or safety switches.
PLCs consist of components such as:
central processing unit (CPU)
digital inputs
analogue inputs
digital outputs
analogue outputs
power supply module
communication module
memory
compact controllers – consist of one module
compact controllers that can be expanded with additional modules, e.g. JUMO variTRON 300
modular controllers – with several modules, used in automation systems for the control of process and production lines, e.g. JUMO variTRON 500
relay output
transistor output
triac output
Programmable logic controllers are widely used in various industries to have complex process control. They are used wherever production is predictable enough to be automated. These versatile microprocessor devices are designed to control, among other things, the operation of machines on assembly lines in factories, lighting, food packaging, machine tools or pumping stations in sewage treatment plants.
One of the reasons why programmable logic controllers are so popular is their modularity. This means that you can mix different types of input and output devices best suited to your application.
Programmable logic controllers can be programmed using a standard computer and PLC programming software.
Ladder Diagram (LD)
Sequential Function Charts (SFC)
Function Block Diagram (FBD)
Structured Text (ST)
Instruction List (IL)
Ladder logic programming is a graphical programming language. In this programming language, all elements are represented using diagrams. It is simpler for the average programist and easier to learn than the average classical controller programming language.
Choosing the wrong PLC for a particular application can result in, among other things, problems in its interaction with other equipment or difficulties in installation in the machine. How to avoid these problems and choose the correct programmable logic controller?
Determine how many and which inputs/outputs you will use in your project, including whether they will be analog inputs (voltage or current), temperature or pulse inputs and transistor or relay outputs.
Note: When you have chosen the appropriate number of input and output circuits, add about 15% more to it. This will avoid problems when the installation is expanded in the future.
Check how much space you have for the controller
Decide which functions you need
Ensure that the controller supports the communication protocol to communicate with your other devices
Verify the number and type of ports on the controller, and verify the possibility of expansion with additional ports
Any doubts? Contact us – together we will choose the right device for your application.
