To add or update/upload PEN Number of the students, follow the given path:
SIS-->Enrollments-->Update Student details--> Select class and click on get-->Select Personal Education No's Click on student/parents PEN Number
against the respective student and click on Tick Mark.
Note :
If you want to upload click on student/parent PEN the file format will be downloaded, update it-->click on Browse(CSV Only)-->click on upload.