Practical Tips and Techniques
Programmable logic controllers (PLC) use a cyclic scan. The time that it takes to complete one scan is called Scan Time. Typical scan times range from 10 milliseconds to 10 microseconds. This translates from 0.01 to 0.0001 seconds per PLC scan. Understanding how the program scan will help us in programming and troubleshooting the PLC. … Read more
PLC memory is very similar to personal computer memory. There is the operating system and firmware of the processor and connected modules. PLC programs and data that are used by the program are also stored in the memory. We will now look at the basic understanding of memory in the PLC. Looking at two examples … Read more
We will now look at another way of programming our palletizer using the PLC. How many ways can you program the PLC for the same function? The answer is a lot of different ways. You can have ten different programmers working on the same program and get ten different automatic control PLC programs. Sure they … Read more
We will apply the five steps to PLC program development to a palletizer example. Our example will allow you to determine how many layers of boxes you want on each skid. Developing the PLC program is a process that can be clearly defined. In our series on the five steps to PLC program development, we … Read more
We will apply the five steps to PLC program development to a pick and place robot example. The example will use a BRX PLC communicating to Factory IO (3D Software Simulator). Developing the PLC program is a process that can be clearly defined. In our series on the five steps to PLC program development, we … Read more
Understanding how the PLC will scan and update your program is critical in programming and troubleshooting your system. Typically a PLC will solve your logic from left to right, top to bottom. The status of the memory from the previous rung, are available for the next rung to use. We will look at a few … Read more