XIC stands for Examine If Closed. What is the behavior of a normally open XIC contact when its input is energized?

• A. The contact closes and allows current to flow
• B. The contact opens and blocks current
• C. The contact toggles
• D. The contact remains unchanged

Answer: (A)

In ladder logic, a normally open contact conducts only when its controlling input is on. XIC, short for Examine If Closed, evaluates to true when the input is energized. When the input is energized, the normally open XIC closes, allowing current to flow through the rung. If the input isn’t energized, it stays open and blocks current. So the contact closes and permits current flow when energized.