Building a PLC Program That You Can Be Proud Of – Part 1

What is the best way to program a PLC?  My answer is simple. The best way is one in which someone can look at your program and understand it. I cannot stress the need for good documentation of your program enough. The best programs are ones that I can return to after several years and … Read more

Who Else Wants To Know How A PLC Scans?

Programmable Logic Controllers (PLC) will scan very quickly. This can be anywhere from 1 to 20 ms, translating into 1000 to 500 times each second. But what exactly is a scan? A scan is when the PLC will complete the following: Read Inputs: Look at all of the inputs to the programmable controller. Digital, Analog, … Read more

Who Else Wants To Lean PLC Programming For Free?

I have always been an old-school programmer. Hardware in front of you hooked up to all of the I/O. I have recently looked at the automation direct do-more designer software solution. The Do-More Designer Software will allow you to build your ladder logic, download it into a simulator (which comes with the software), and run … Read more

Here’s a Quick Way to Understand PLC Inputs and Outputs

The term I/O means Input/Output. I/O can come in two different types; Discrete or Analog. Most people starting out learning about programmable logic controls (PLC) are taught all about discrete inputs and outputs. Data is received from devices such as push-buttons, limit-switches, etc., and devices are turned on such as motor contactors, lights, etc. Discrete … Read more

Here’s a Quick Way to Convert Grey Code into Binary for PLC

Grey Code Grey Code is used because only one bit of data will change at a time. The following chart shows the conversion of Grey Code to Binary. Number Binary Code Grey Code Number Binary Code Grey Code 0 0000 0000 8 1000 1100 1 0001 0001 9 1001 1101 2 0010 0011 10 1010 … Read more

What Everybody Ought to Know About PLC (Programmable Logic Controller) Numbering Systems

plc basics programmable logic controller

Programmable Logic Controllers (PLC) are the same as computers. They only understand two conditions; on and off. (1 or 0 / Hi or Low/ etc.) This is known as binary. The PLC will only understand binary, but we must display, understand and use other numbering systems to make things work. Let’s look at the following … Read more