Yes, use the facility autocodes feature of the OM500. You can set up a unique 6 digit facility code that will be plugged into an equation that will generate the same code for users 001-500. When adding users, select the facility code you want and the codes will automatically be set up. As long as the same facility code is used in all of the locks.
For additional information, please see the OM500UserManual.pdf attachment below. Page 95 of the printed document or 105 of the PDF will walk you through this process step by step.