The Timer Delay Off (TOF) timer functions the opposite of the TON timer.
De-Energizing I:1/0 causes the timer to run for 4.5 seconds. The DN bit is initially set.
At the end of 4.5 seconds the output (DN) goes off. When the input is energized the timer resets to 0.
If the input I:1/0 is turned on during the timing interval (for example, after 2.7 seconds), the timer resets to 0.
Timer Delay Off (TOF)