While you wait for answers, we may have found some information which could help you.
Click here for 500 Cash Register
PE code on screen of Royal 500dx?
royal 480nt?
How to program a Royal 500dx Electronic Cash Register?
How do I program my Royal 480nt Tax 1 key?
how to emove PE error?
My Royal CMS-8169 has stopped printing customer receipts. ?