Practical Tips and Techniques
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
The hostlink communication protocol is a method developed by Omron for communication to PLCs and other equipment. This ASCII-based protocol is used over RS232 or RS422/RS485. It is a many-to-one implementation, meaning you can communicate with up to 32 devices back to a master. (1: N) This communication on the industrial floor can control PLCs, Temperature … Read more
PLC programming involves both direct and indirect addressing. Direct address programming involves writing each ladder logic rung to do the operation required. We often forget about using powerful indirect addressing to solve our logic. Indirect Addressing – Faster PLC Program The below-animated picture will show a simple example of using indirect addressing. This will use … Read more
Learning programmable logic controllers (PLC) include understanding of the basic components, language, numbering systems, program development. PLC Basics will help in your learning of the programmable logic controller. If this is your very first time programming a PLC, we suggest you check out our beginner’s guide to programmable logic controllers. Hardware and Software – PLC … Read more
A collection of random thoughts on PLC programming and doing more than just basic logic and making your program intuitive. PLC programs usually control the logic between the inputs and outputs. If this turns on and that is not on, then this output is on, blah blah blah. Programmable logic controller programs can go far … Read more