Practical Tips and Techniques
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
We apply the five steps of PLC development to a plc shift register example. This PLC programming example will use a shift register to reject a product on a conveyor. When programming a PLC, you need to track what has previously happened. Shift registers allow you to do just that. We will look at a … Read more
We will apply the five steps to PLC Program development to our following programming example of a process mixer. The process mixer will be programmed using ladder logic. We will discuss each step of the PLC program development. 1 – Define the task: How does the process mixer work? A normally open start and normally … 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