It is essential to understand that you cannot deal with some project without proper tools. It does not matter whether you are a professional or an amateur; because using an appropriate tool will help, you deal with any assignment with ease.
This is true when it comes to programming a control system, a measurement and repairing a faucet.
Due to this particular need, software vendors allowed numerous programming methods to be used for programmable logic controllers so that engineers can easily transit from old automation methods.
This particular method is unique engineers could become programmers and use ladder logic to deal with automation tasks across different industries.
The most popular programming methods when it comes to PLC and making software are textual, function block, ladder diagram, simulation and modeling, and statechart.
Ladder Diagram
We have to start from the very beginning by saying that the ladder diagram entered the scene and evolved during the ’60s when the automotive industry requires a more self-documenting and flexible alternative to timber cabinets and relay logic.
That is the main reason why microprocessor-based systems were introduced, and this particular software was designed to help you mirror electrical diagrams so that you can build the control panels from the relay.
This particular software that we know as a ladder diagram or ladder logic executes and looks similarly as electrical diagram so that transition could be painless and without additional training.
The idea is that you imagine left rail as the power bus and the right rail as the ground bus. Power flows through different series of open and closed contacts with the idea to power up a coil. Have in mind that open contacts tend to block power and closed contacts tend to pass it through.
When it comes to ladder logic, each contact, as well as a coil, is linked to a Boolean memory location, and series contacts act like, and parallel contacts act like or. Of course, everything is executed from left to right and top to bottom, all at once.
You will have to think also about the unseen memory management stack and scanning engine. Since physical inputs are stored and read inside the memory table, the ladder logic will run and write from the memory table for outputs, inputs by presenting intermediate values.
As soon as the logic cycle ends, physical outputs will be updated with memory table values, and since most ladder representations can efficiently perform both writes and reads, you do not have to wait for execution cycle to end.
If you wish to handle more complicated tasks such as counters, timer functionality, math or PID, you will have to create ladder representations that will provide you call functions directly on a ladder rung.
These functions will have an input terminal that will allow you to execute the function, as well as an output terminal that will provide you successful execution. You will be able to drop these functions into the ladder diagram, and they will execute based on the power flow.
If you wish to learn more on this particular programming language you should click here for more information.
Advantages of Ladder Logic
- Self-Documenting and Intuitive – Have in mind that ladder diagram contains a proper and high-end graphical representation, which is entire, based on circuit design concepts that most engineers understand. Since it features familiarity of the environment, the learning curve that will provide you with the ability to start with the Ladder Diagram is low. Have in mind that you will be able to develop fundamental programming skills in a matter of days. That is the main reason for its popularity especially if you wish to make new apps for PLCs that you have to maintain or debug by personnel that does not feature software training, but they can be planted, technician and electricians.
- Amazing Debugging Tools – Most modern debugging tools are connected with ladder diagram, and you will be able to learn how to follow the power flow so that you can understand the debug faults and diagram logic, which will increase the overall perspective of your knowledge and software capabilities.
- Efficient Representation – Since ladder logic features a design that completely mirrors electrical circuits, it is the most convenient way to represent any form of discrete Have in mind that ladder diagram is the most intuitive language that will help you create a digital logic based on the operations you wish to make.
To understand the ladder logic on everyday example will help you deal with it better and that is why you should visit this link: https://www.wikihow.com/Design-and-Run-Simple-Ladder-Diagram-of-Industrial-Garage-Door-Opener-Using-RSLogix-5000.
Disadvantages of Ladder Logic
- Hierarchical Logic Encapsulation and Data – The main limitation of ladder logic and diagram is its inability to encapsulate the same code so that you can reuse it in the future. In case that you programmed everything in the ladder diagram, have in mind that everything will be unmanageably long, which means that debugging, coding and editing will be much more challenging than other programming languages for PLCs. Since hierarchical programming is an essential requirement if you wish to make a modern software design, most major ladder diagram packages feature function blocks and functions that you can call by using ladder rung. Have in mind that most ladder programs will support a limited number of program blocks and subroutines, which means that it will be challenging to break it into manageable parts.
- Lousy Data Structure – Generally speaking, ladder diagrams tend to address memory by using single memory registers or bits, and you can both write and read to variables by using any part of the program. Therefore, it is challenging to protect data or to group it as a structure. Since data addressing is on a low level, it is simple to access wrong registers and cause unexpected behavior. Therefore, it will be challenging to protect internal data, and that creates an exceptional risk that someone can modify the internal data by using faulty code somewhere inside the program. You can use named variables but have in mind that you will overlap memory locations by creating them. Since most prominent editors feature tools that will help you understand where memory registers are written and read, you will be able to maintain it so that you can reduce the possibility for conflicts.
