I would solve this via a password-protected message text.
In this you enter the parameters that you want to change.

Attached example:
With the input I1 a message text is called, which prompts you to enter the password. Here it is 6128724, but can be changed. The password is the number stored in the ON parameter of the counter. The OFF parameter then contains the number +1 (618724 + 1 = 618725).
The second message text is only released if the password has been entered correctly. In this you enter the parameters that you want to change.
By the counter is the protection enabled. This has the background that the parameters of the counter in the system menu can not be viewed when switching to the operator mode.
By the parameters that you insert in the second message text must the protection also switched on.