Practical Tips and Techniques
A flip-flop circuit in a PLC usually has one input and two outputs. When the input is activated, the two outputs alternately latch on/off opposite each other. It is used to toggle (latch) work on and off with just one input. In the PLC, it is a single input that will toggle an output on … 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
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 inputs, Discrete and analog. Discrete inputs are either ‘ON’ or ‘OFF’; 1 or 0. You can think of them as a single switch. Analog inputs have a range to … 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
We will now look at the secret of using timers in the PLC. Timers are used in the majority of PLC programs. There are also a wide variety of off-the-shelf industrial timers that you can use. The implementation of timers can be vast; however, it all starts with a TIMING CHART. Timing Chart – Secret … Read more