Practical Tips and Techniques
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
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