Thank you for your post.
FileMaker Pro does not have the built-in ability to communication through the RS232 port. The Troi Serial Plug-in is well known, as there may also be other plug-in alternatives. You can see a list of plug-ins on our web site:
There is an ODBC driver supplied with FileMaker Pro that allows other applications to access FileMaker data.
FileMaker Pro is certified to work with the following SQL databases:
Microsoft SQL Server 2000/2005, MS SQL 2008
Oracle 9i, Oracle 10g, Oracle 11g
MySQL 5.0/5.1 Community Edition
I have used the Troi Serial plug-in, and can highly recommend it. Just make sure you have a good read of the instructions that come with it, and you should be up and running in no time.
The trial version will let you completely test your solution without any limitations (just a nag screen).