Practical Tips and Techniques
Wiring outputs to the plc like relays and motors.
We will now wire a stack light to the Click PLC. Stack lights are usually modular stackable components that provide a visually illuminated and audible indication for machines, systems, and processes. They are usually located on top of equipment to provide this notification to personnel in the area. Stack lights are also known as signal … Read more
Contact and coil instructions are in every PLC program. The Productivity Suite Software consists of more than 82 instructions divided into 13 categories for the PLC. Contacts and Coils are two of the categories of instructions. Contact instructions include NO / NC, NO Edge / NC Edge and Compare. Coil instructions include Out, Set, Reset, … Read more
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
We apply the five steps of PLC development to a plc shift register example. This PLC programming example will use a shift register to reject a product on a conveyor. When programming a PLC, you need to track what has previously happened. Shift registers allow you to do just that. We will look at a … Read more
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 outputs, Discrete and analog. Discrete outputs are either ‘ON’ or ‘OFF’; 1 or 0. You can think of them as a single light bulb. Analog outputs have a range … Read more
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