You can take the CLD-R until you pass. If you are taking the exam at Pearson Vue, there is 15 calendar day wait between attempts.
National Instruments' Recertification Policy and Process and preparation resources can be found here: http://zone.ni.com/devzone/cda/tut/p/id/9605
If you have further questions, please email firstname.lastname@example.org
Certification Development Group Manager
Hello, Can someone please tell me how many times are you allowed to take the CLD-R?
Theoretically once every two years should be just about all you need.