Five Steps to PLC Program Development

steps plc program development

Programming a PLC can sometimes be a daunting task. The best method is to break the task into smaller steps. These are the steps that I have used for years to develop PLC programs. We will apply them to a die-stamping application. Step 1 – Define the task: What has to happen? This is written … Read more

Who Wants to Learn About On Off and PID Control?

Process control can be a bit intimidating. We will try and break down both On/Off and PID control in a fun way. This is a simple analogy without any math. On-Off Control Explained On/Off control can be used effectively with temperature control. Everyone’s house usually has a temperature controller that uses an On/Off control. The … Read more

How PLC Inputs Work – Discrete and Analog

This post is a further follow-up from my original ‘Here’s a Quick Way to Understand PLC Inputs and Outputs.’ There are two different kinds of PLC inputs, Discrete and analog. Discrete inputs are either ‘ON’ or ‘OFF’; 1 or 0. You can think of them as a single switch. Analog inputs have a range to … Read more

How to Implement Omron PLC Host Link Protocol

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

The Secret of Using Counters – PLC Programming

We will now look at the secret of using counters in the PLC. (Secret Using Counters) Counters are used in the majority of PLC programs. This is especially true if part of your SCADA system. Counters like the animated picture above count things. In this situation, we count the number of turns the little guy … Read more

The Secret of Using Timers – PLC Programming

We will now look at the secret of using timers in the PLC. Timers are used in the majority of PLC programs. There are also a wide variety of off-the-shelf industrial timers that you can use. The implementation of timers can be vast; however, it all starts with a TIMING CHART. Timing Chart – Secret … Read more