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

Here’s a Quick Way to Connect RS232 Equipment

Most programmable controllers will come with an RS232 communication port. This recommended standard (RS) has voltage signals between 3 to 15 volts DC concerning the ground/common pin. RS232 devices are called DTE (data terminal equipment) or DCE (data communication equipment). The maximum cable length for the communication cable is 15m; however, depending on the environment, … Read more

The Secret Of Getting Rid Of Noise On Your Analog Signal

In industrial environments, we often get noise on the analog signal input to PLCs or other controllers. Motors, lousy wiring, etc., can generate noise. Placing a 1- 100 uF capacitor on the input signal and ground (common to the cabinet)  will reduce the noise the input receives. If you have any questions or need further … 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