ACC Automation: PLC & Industrial Control Learning
Practical Tips and Techniques
We are using Modbus TCP protocol, reading ten registers in the PLC, and displaying a bar graph in Excel. e will use Visual Basic for Applications (VBA) to communicate with a PLC. Previously we have used VB6 to communicate Modbus TCP. Sequence for Modbus TCP on Excel using VBA The following steps will be done: … Read more
Utilizing the CX Server DDE Manager will allow us to provide a link to the information in the Omron PLC. This link can be placed on an Excel spreadsheet. Charts, graphs, etc., can be made from the data. We will create links on an excel spreadsheet from a CQM1H and a CP1L PLC. The information … Read more
We will use VBA in Excel to communicate to an Omron PLC. This will use the serial host link protocol. ACC Omron Host Link VBA In Part 1, we used VB6 to communicate from the computer to the PLC (Host Link Protocol). We will now use Visual Basic for Applications (VBA) to accomplish the same … Read more
Manufacturers have software to program the programmable logic controller (PLC) or the human-machine interface (HMI). However, there are a few free tools that will help in the development of your PLC programs. We will look at three software tools and show how beneficial they can be to you. Free PLC Software Tools Synergy – Share … 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
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