Practical Tips and Techniques
We will now create a PLC with HMI Training and learning environment. We will use the Automation Direct Do-More programming software tied into the Advanced HMI learning package via Modbus TCP. All of the software is free and fully functional. Learn PLC programming and use a powerful HMI (Human Machine Interface) easily and freely. Setting … Read more
Sending email messages from the PLC sounds like an easy task. However, very few applications do this on the production floor. This is probably due to the networks involved, and authentication can be complicated. In our example, we will use a restricted Gmail SMTP server so that no authentication will be required. We will walk … Read more
PLC programs are typically written in a particular application on a personal computer, then downloaded to the PLC. This downloaded program is similar to compiled code to keep the program efficient. The program is stored in the PLC in battery-backed-up RAM or non-volatile flash memory. Five Different PLC Programming Languages Albert Einstein said, “The world … 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
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
We will look at how to troubleshoot a plc racing condition. Two examples are explained in racing conditions in the PLC. The PLC will update only at the end of the program logic. Items set will not happen until the I/O is refreshed. How to trigger events when you want them is discussed. Your control … Read more