Normally open (NO) contact concept.

Normally open (NO) contact concept.

This is PLC Program for NO contact.

Normally open contact is known as NO contact. When the quantity has signal state 1, the open contact closes and therefore the signal state of the output is changed.

When the quantity has signal state zero, the open contact closes is not activated and therefore output state is zero.

If two NO contacts are connected in series, the power flows once all contacts are closed

If two NO contacts are connected in parallel connection, the power flows once one contact amongst all contacts are closed.

Example of the NO contacts.

In above example two NO contact s are connected in series (tag 1 and tag 3). When both signal state is 1 then tag 2 state is 1.