TA Timer (Accumulated, Retentive Timer)

The TA timer functions like a TON timer with two differences:

• If the input condition falls while the timer is running, the timer stops counting--but the current value is retained. This means that when the input condition rises and the timer restarts, it continues to count from the point at which it stopped.
• A TA timer must be reset using the Reset Timer Function. This resets the current value and causes the Timer Out bit to turn OFF.

When the input condition of a TA timer rises (positive RLO):

• The Timer begins to decrement.
• When the current value of the timer reaches 0, and the timer's input condition is still ON, the Timer Out bit turns ON.
  The Timer Out bit remains ON regardless of the input condition.