Practical Tips and Techniques
We will apply the five steps to PLC Program development to our following programming example of a process mixer. The process mixer will be programmed using ladder logic. We will discuss each step of the PLC program development. 1 – Define the task: How does the process mixer work? A normally open start and normally … Read more
A data logger is also known as a data recorder or data acquisition. It is a method to record data over some time and events. The recorded information can come from sensors in the field. They can be digital or analog. Digital data can be used for counts, times, events (motor overload), etc. With the … Read more
Simple mail transfer protocol (SMTP) is the email protocol for sending information. We can use this ability to email from our data logged from the PLC. Faults or errors the PLC detects can be emailed to individuals for correction. Shift reports on productivity can be automatically emailed to recipients. Note: Google is removing “Less Secured … Read more
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
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
