Question

Could a TON timer be used to achieve the same goal as a TOF timer? If so, how would it be accomplished?

Answer 1

TON

1. When start measurement is on (turned on), the elapsed time .ET will increase by the specified time-based units because the TON instruction is triggered.
   The timer measurement bit .TI turns ON.
   The timer output bit .Q turns OFF.

2. When the elapsed time .ET increases to equal the preset time .PT, the elapsed time .ET keeps the current value.
   The timer measurement bit .TI turns OFF.
   The timer output bit .Q turns ON and allows power to pass.

3. When start measurement is off (turned off), the elapsed time .ET will be reset to 0.
   The timer measurement bit .TI turns OFF.
   The timer output bit .Q turns OFF.

TOF

• When start measurement is on (turned on), the elapsed time .ET will be reset to 0 because the TOF instruction is triggered.
  The timer measurement bit .TI turns OFF.
  The timer output bit .Q turns ON and allows power to pass.

• When the TOF instruction is triggered and the measurement start bit is turned OFF, the elapsed time .ET will increase by the specified time-based units.
  The timer measurement bit .TI turns ON.
  The timer output bit .Q remains ON.

• When the elapsed time .ET increases to equal the preset time .PT, the elapsed time .ET keeps the current value.
  The timer measurement bit .TI turns OFF.