Practical Tips and Techniques
A one-shot in the PLC will turn an output on for one scan. This is used to trigger events that should only happen once. An example of this would be to increment a value in memory. If a one-shot is not used, then every scan of the PLC will increment the value. What is a … Read more
This post is a further follow-up from my original ‘Here’s a Quick Way to Understand PLC Inputs and Outputs.’ There are two different kinds of PLC outputs, Discrete and analog. Discrete outputs are either ‘ON’ or ‘OFF’; 1 or 0. You can think of them as a single light bulb. Analog outputs have a range … Read more
I have been writing PLC programs for over 20 years. I often get asked what the best way to learn PLC programming is. Programming in the way I was taught in college was with the Motorola 6809. (Yes, I know that I am dating myself) This was microprocessor programming, but it was the best way … Read more
We will now look at the secret of using counters in the PLC. (Secret Using Counters) Counters are used in the majority of PLC programs. This is especially true if part of your SCADA system. Counters like the animated picture above count things. In this situation, we count the number of turns the little guy … Read more
