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
All programmable logic controllers (PLC) have the same numbering system at their core. This is the same with all computers as well. The status of any memory location can be either on or off. A one (1) will represent an on or “True” status and zero (0) will represent an off or “False” status. This … Read more
EasyPLC Software Suite is a complete PLC, HMI, and Machine Simulator Software package. This PLC learning package includes the following: Easy PLC – PLC Simulation that will allow programming in Ladder, Grafcet, Logic Blocks, or Script. HMI System – Easily create a visual human-machine interface (HMI) Machine Simulator – A virtual 3D world with real-time … 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
PLC outputs are the next component of our PLC block diagram. The PLC program will control the outputs of the PLC. Controlling outputs is one way to get the inputs to change. We will be looking at digital and analog outputs that can be wired to the programmable logic controller. PLC troubleshooting outputs will also … Read more
PLC inputs are one component of our PLC block diagram. The output actions of the PLC will be controlled based on the inputs. We will be looking at digital and analog inputs that can be wired to the programmable logic controller. We will be looking at wiring of a normally open (NO) push button, normally … Read more