Practical Tips and Techniques
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 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
Now You Can Have Robust Data Logging for Free – Part 12 HTML and Scripting Languages We have the following accomplished: PLC program Visual Basic Program Data collected in a Database IIS web service established ASP Script Written Let’s take a closer look at the ASP Script ( AccRL.asp) that was written in part 11: … Read more
Now You Can Have Robust Data Logging for Free – Part 11 HTML and Scripting Languages We have the following accomplished: PLC program Visual Basic Program Data collected in a Database IIS web service established The IIS web service machine must have the Microsoft Access Database Engine 2010 installed. The following link can obtain this: … Read more
Now You Can Have Robust Data Logging for Free – Part 10 Computer Web Server (IIS) We have come a long way. The PLC program has been written. The primary visual program has been reported. Information is now being collected from the Do-more PLC via Modbus TCP and stored in a database using visual basic. … Read more