Omron PLC Node-RED Serial Communication

PLC manufactures have their own proprietary protocols. These methods of communication will allow you to program the controller. Other protocols will allow you to collect and log information from the programmable logic controller. Node-RED has the ability to read and write to the Omron controller using special protocol commands. We will connect Node-RED to the … Read more

Capacitive Pushbutton Sensor Switch /Indicator

We will now look at the capacitive pushbutton sensor switch and indicator. Normal pushbuttons on a panel are usually a mechanical device. They can become “sticky” when too much dirt or oil is present. Capacitive push buttons do not have moving parts to stick, so the life expectancy is increased. Disinfectant sprays can be applied … Read more

Wiring 3 Wire DC NPN and PNP Sensors

Wiring 3 wire DC sensors can be confusing. I recently received a question on PNP and NPN sensors. They wanted an explanation of what a sink is and how to wire one. Confusion over the Normally Open and Normally Closed function of the sensor is also a common question. Several diagrams will show a resistor … Read more

Universal Signal Conditioner and Isolator

Signal conditioners are used with analog current and voltage signals. They have the ability to change your input analog signal to another output analog signal. As an example, we can have 4-20mA analog input and change it to a 0-10VDC output signal so we can wire this into our PLC. Typically signal conditioners will also … Read more

Wiring an NPN PNP Sensor to the Click PLC

A proximity sensor (switch) is able to detect object presence without physical contact like a limit switch. No physical contact means that the switch has no parts that will wear out. The life span of the sensor is increased with less maintenance. A capacitive proximity sensor will detect ferrous and non-ferrous objects. The sensor works … Read more

Wiring Push Buttons Switch to Click PLC

We will now look at wiring a click plc with selector switch and pushbuttons. A push button (pushbutton) is a simple human interface for controlling some aspect of a machine or process. The push button requires a force to push the button to change the electrical operation from off to on or vice versa. The … Read more