After modifying the program, it is necessary to save the program in the memory of the controller. This is what the button is for  (Save), which is automatically displayed when a change is made in the program. After pressing this button, the changed program is saved and the button disappears. If we do not save the program, then the changes made will be lost in the following cases:

•in the programming mode, we select another program

•we leave the programming mode

•a power failure occurs