It would be my guess that the DB is MS SQL. But that's just the data. The functionality would need to be re-created. All the integrations with the devices would need to be recreated.
Do you have a compelling reason to leave it? Is there rather a way to access the data (depending on the database)?
Generally speaking there are two avenues to pursue to move the data:
If you can set up an ODBC connection, you can use this to import the data from another system into FileMaker.
If you can export the data into any file with any number of different possible formats: Excel, tab, csv...
You can then import the data from those files into FileMaker. You can create the table as part of the import process--in cases like excel, you can use column headers to name your fields.