on the older dial type transponders you avoid this by starting from the right and going left as you enter numbers.
So, for instance 4583, you’d do the 3 first and the 4 last.
By doing it this way you never have an even numbered value in your 10’s or 1’s dial… so things like 7700 can not happen… You might momentarily be 7783, or 7583… But you’d never be 7700 or 7600…