Two XIC (examine if closed) inputs are placed in parallel, this would be equivalent to which logic circuit?

Two XIC (examine if closed) inputs are placed in parallel, this would be equivalent to which logic circuit?

• A. AND
• B. OR
• C. NOR
• D. NAND

Answer: (B)

Parallel XIC inputs implement OR logic. An XIC is closed when its input is energized, so each parallel path can complete the rung independently. If either input is on, at least one path closes and the output energizes, matching OR behavior (true if any input is true). If both inputs are off, the rung isn’t completed and the output stays off. In ladder logic, placing inputs in series would require both to be true (AND), while NOR or NAND would need inverted outputs or additional zeroing, which isn’t provided by this simple parallel arrangement.

Parallel XIC inputs implement OR logic. An XIC is closed when its input is energized, so each parallel path can complete the rung independently. If either input is on, at least one path closes and the output energizes, matching OR behavior (true if any input is true). If both inputs are off, the rung isn’t completed and the output stays off. In ladder logic, placing inputs in series would require both to be true (AND), while NOR or NAND would need inverted outputs or additional zeroing, which isn’t provided by this simple parallel arrangement.