How to set pass/fail in scorm for moodle LMS to recognise

We have assessment activity which requires the student to score 80% to pass with only 1 attempt.  Moodle is not recognising completion so if student goes in and wants to exit prior to completion, moodle considers it 1 attempt and locks the student out.  What scorm settings and triggers should we be using to ensure that moodle recognises when student hasn't completed a course compared to when they have complete?