When a timer tag is used with the WAIT instruction, what does the robot wait for?

• A. The robot waits for either I/O status to be true or the timer to expire, whichever occurs first.
• B. It ignores the timer tag and waits for a fixed delay
• C. It only waits for the timer to expire and ignores I/O
• D. The robot waits for an external operator to press a start button

Answer: (A)

When you use a timer tag with the WAIT instruction, the robot pauses until either an I/O condition becomes true or the timer expires, whichever happens first. The timer tag provides a timeout, so you’re protected against waiting forever, while the I/O condition can release the wait sooner if the event happens earlier. If the sensor or input changes state before the timer finishes, the program continues right away; if nothing happens in the allotted time, the timer expires and the program continues on that path. This dual-trigger behavior is what makes using a timer tag with WAIT flexible and responsive, rather than waiting for a fixed delay or ignoring I/O.