A simple example of an 'XIO' operator would be ___.

A simple example of an 'XIO' operator would be ___.

• A. Normally-Open pushbutton
• B. Toggle switch
• C. Normally-Closed pushbutton
• D. Close on rise thermostat

Answer: (C)

The thing being tested is how an XIO (Examine If Open) is used to represent an inverted input in ladder logic. XIO checks for an open condition, i.e., it behaves like a NOT of the associated input. The simplest hardware that naturally provides an inverted state is a normally closed pushbutton. In its idle state it’s closed (conducting), and when pressed it opens (not conducting). Wiring an XIO with a normally closed pushbutton shows the inverse behavior clearly: the rung is true when the input is not activated (open) and false when it is activated, illustrating the NOT logic. A normally-open pushbutton isn’t inversion by itself; it’s closed only when actuated, so it doesn’t demonstrate the inverted condition. A toggle switch could be either normally closed or normally open depending on its wiring, making it less direct as a basic example. A thermostat that closes on rise is a different kind of device with a specific temperature-triggered action, not the simple input inversion concept embodied by XIO.

The thing being tested is how an XIO (Examine If Open) is used to represent an inverted input in ladder logic. XIO checks for an open condition, i.e., it behaves like a NOT of the associated input. The simplest hardware that naturally provides an inverted state is a normally closed pushbutton. In its idle state it’s closed (conducting), and when pressed it opens (not conducting). Wiring an XIO with a normally closed pushbutton shows the inverse behavior clearly: the rung is true when the input is not activated (open) and false when it is activated, illustrating the NOT logic.

A normally-open pushbutton isn’t inversion by itself; it’s closed only when actuated, so it doesn’t demonstrate the inverted condition. A toggle switch could be either normally closed or normally open depending on its wiring, making it less direct as a basic example. A thermostat that closes on rise is a different kind of device with a specific temperature-triggered action, not the simple input inversion concept embodied by XIO.