I'm trying to create a filled tank auto / Manual one tank

[DonRoonin]

Well, the idea I've been having trouble implementing is a stop function that halts everything; in this case, it would interrupt the tank filling process, whether in automatic or manual mode, as a form of spontaneous interruption. It's not the same as the existing 'Stop' button, since that one just ends the entire program execution.
Another way to refer to this function I want to implement could be 'freeze,' since once activated, nothing will move—or more precisely, the tank filling will stop in a semi-permanent way. I also plan to make it so that when 'Reset' is pressed, the system resumes normal operation.

In summary, there would be two things:

• A button to freeze the tank filling process, regardless of whether it's in automatic or manual mode; the tank will stop filling.

• A button to reset the tank functions, starting all values from zero.

[altenbach]

So you basically want a "pause" function, right?

For the "reset", do you want to instantly go to a zero level or should it go to zero at the define speed.

[DonRoonin]

Yes, and it should instantly go to zero.

[DonRoonin]

Could you help me, I really don't know how to do that?

[altenbach]

For the "pause", you just need to change the increment to zero while paused. (Use a switch action boolean)

For the "reset", You need to set all controls to a defined value using local variables and set the talk level stored in the shift register to zero.

There are very basic requirements that are easy to implement. Here is one (of many!) possibility. Make sure you understand the purpose of every single code element.