What Is NO NC & COIL Functions And How To Use It In WinProladder?

As we know, we make programs of PLC, in ladder logic language. There are some requirements of making PLC program, for any manufacturer, or brands' PLC, or programming software, the first requirement is, you should know ladder logic language. This is no doubt, a very basic language and a basic requirement to write a PLC program.

There are some components of this ladder logic language, which are very useful and will be using these in our PLC programming projects. List and definitions of the main components of ladder logic language are given below;

• NO = Normally open contact. (normally open contact means, the contact is open in normal condition. When there is no current flowing, this contact open the circuit. When current will start flowing from this contact, this will be energized and will make circuit close.

• NC - Normally close contact. (normally closed contact is the opposite of normally open contact. Normally closed contact means, when there is no energy, this contact is close. When it will be energized, this make circuit open for flowing current. This means when we will supply to this contact, this will switch off the circuit.

• COIL - Coil is a very common contact, which we will use in the outputs of the PLC program. This is same as we have relay's coil or coil of magnetic contactor.

From given below figure, you will get an idea of the internal structure of these contacts.

This is information of basic components of ladder logic programming or language. now let's discuss about how we can use these components to make our Fatek PLC program  in winproladder software. In your software screen, you can see the function strip there, as shown below.

In the third line, there are ladder components, such as normally open, normally close, coil, SET and RESET components that we will use rarely in our programming. First one is mouse option. The second component is “Normally open” contact. The third function is “Normally close” contact. Function number six is “COIL” contact. These three contacts are main components and we will use very commonly in our programming. Click on the screen, where you want to put this contact. Then, click on any contact function from the menu, and a pop-up will appear on your screen.

For-example, I want to add NO (normally open contact). When I click on NO (normally open contact) function from the menu. Pop up will open as like below.

Write input number “X0” and press “ENTER” button. NO (normally open contact) will be placed as shown below.

This is how you can placed contacts in your programming screen. Please watch this video tutorial from below for better understanding.