Hello,
There is no master password on our devices. Have you purchased these devices directly from us?
If yes, then I would recommend contacting your sales manager for a manufacturing file, which will contain the passwords of the devices.
However, if they were purchased from a third-party reseller, I'm afraid there isn't much that can be done here. Please keep in mind, that RUT240 also has a unique password, so the newer batched will have the same issue.
Best regards,
DaumanatsG