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

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 an Inductive NPN PNP Sensor – Click PLC

We will now look at wiring an NPN and PNP inductive proximity 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 … 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

Wiring Interposing Relays – NPN PNP Isolation

Wiring Interposing Relays - NPN PNP Isolation

We will now look at wiring interposing relays to connect an NPN and PNP sensors into the PLC. Interposing relay means a device that will separate two different circuits. The isolation can be for current consumption, voltage differences, voltage references, or a combination of both current and voltage. We can use these relays to help … Read more

Here’s a Quick Way to Wire NPN and PNP devices

Here’s a Quick Way to Wire NPN and PNP devices I often get asked how to wire NPN and PNP devices to the programmable logic controller. This can be unclear at first when looking at the wiring diagrams. I have managed to destroy a few sensors in the process….. so let’s get started, and I … Read more