Of course all this varies from state to state. In the state where I was a PO (MD), you did not violate probation unless you are convicted of a new charge while on probation. New charges can be dropped or the person may be found not guilty. There may be a clause in your probation order that requires you to notify your PO if you get a new charge, you might want to look and see if yours has a requirement. It might also have some wording on whether or not you violate by getting arrested.