Hi @cuongho ,
Thank you for your question. Could you send us images of what your scheduler looks like and what settings are being reset.
Using a scheduler to turn a timer on and off is a very possible operation and is a good use case to set up. To save the values we would recommend using a data sampling object to track values like elapsed time.
Here is resource about timers that may provide some assistance: LINK
We look forward to your response.