Shift registers will move (shift) bits in a word (register) to the left or right.
If we look at an example of boxes moving along a conveyor belt, the boxes would represent the bits in the register. The movement of the conveyor would be the shifting of the register that represents the movement of the boxes.
Shift registers are a form of sequential logic, which involves the present inputs and the prior history. All of the prior history is remembered.
We will be making a shift register in PLC Fiddle with the instructions provided. The output of the shift register will then be looked at for a reject area. Let’s get started. Continue Reading!
Just about every program usually has some data comparison instruction. This is the ability to compare information from one area of the controller to another and act on results. The output of this comparison conditions the logical continuity of a rung. PLC Fiddle is a free online browser simulator and has the following compare contact instructions. = (if Equal contact) <> (if Not Equal contact) > (if Greater Than contact) >= (if Greater Than or Equal contact) < (if Less Than contact) <= (if Less Than or Equal contact) We will be looking at these instructions along with some programming challenges. As a system integrator, this ability can prove very useful to you in the field when commissioning your automation system. We will look at these compare instructions and show the parameters required to program them. Our compare challenges will help you gain a good understanding of how we can use compare in the PLC. Trying these challenges with PLC Fiddle is fun and will help you with PLC programming. Let’s get started. Continue Reading!
Counters are used in a lot of PLC programs that I have seen. A timing chart is a secret behind understanding the counter that you need in your application. Making a timing chart before writing the program will ensure that all of the information will be accounted. The secret to using counters is a good review of using these timing charts.
PLC Fiddle has three different counter instructions for us to use in our programs. Count UP, Count Down and Reset. We will discuss the counter parameters and the three different instructions. Our counter challenges will help you gain a good understanding of how counters work in the PLC. Let’s get started. Continue Reading!
Timers are present in just about every PLC program that I have seen. A timing chart is a secret behind understanding the timer that you need in your application. Making a timing chart before writing the program will ensure that all of the information will be accounted for. The secret to using timers is a good review of using these timing charts.
PLC Fiddle has three different timing instructions for us to use in our programs. On-Delay, Off-Delay, and Retentive Timers. We will discuss the timer parameters and the three different instructions. Our timer challenges will help you gain a good understanding of how timers work in the PLC. Let’s get started. Continue Reading!
Last time we discussed the free virtual plc simulator called PLC Fiddle. It will enable you to create simple PLC ladder logic code within your browser. This is an ideal way in understanding PLC concepts for industrial automation. All of the basic PLC instructions that come with most plc units have been incorporated into this virtual PLC software. https://accautomation.ca/plc-fiddle-online-editor-and-simulator-in-your-browser/ PLC Fiddle Video – This will demonstrate the basic functions of the PLC simulator.
Understanding and creating your own programmable logic controller programs on the ladder can be fun. We will be starting with the basic gate logic circuits and convert these to ladder logic.
We will be looking at the AND, OR, NAND, NOR, EXOR, and EXNOR logic circuits using PLC fiddle. This will get you involved in learning and understanding PLC programming. Let’s get started. Continue Reading!