Tag Archives: logic

PLC Learning Series – Memory Backup


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.
PLC Learning Series – Memory Backup
We will now look at the basic understanding of memory in the PLC. Looking at two examples of PLC specifications. We will see how the program is stored and how long data memory will remain when the PLC is not powered up. Let’s get started. Keep on Reading!

PLC Learning Series – What are Outputs?


PLC outputs are the next component of our PLC block diagram. The outputs of the PLC will be controlled by the PLC program. 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 be discussed. This will be done using a multimeter measuring voltage both at the PLC output and across the discrete output load. We will also measure and control an analog signal output. Let’s get started. Keep on Reading!

PLC Learning Series – What are Inputs?


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 closed (NC) push button, 3 wire PNP sensor, and an analog sensor to the PLC. These will all be sinking inputs. Let’s get started. Keep on Reading!

PLC Training Series – Tutorial for Everyone


Invented in 1968 by Dick Morley, the programmable logic controller (PLC) is a simple rugged industrial computer. This free plc training series is designed for everyone to learn about these controllers. PLCs are constantly evolving and continue to be the best option for a variety of industrial automation applications.

Even though the PLC is changing, core items remain the same. We will be discussing this in more depth for each of the components mentioned in the picture above. Let’s get started learning about PLCs. Keep on Reading!

Understanding the PLC Program Scan

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 examples to determine how the PLC will solve logic to illustrate the above program scanning.  Keep on Reading!