It would be good to normalize the catalog and PLC databases. The current form is really quite terible from a database design perspective. A pin list table for each manufacturer? A table for each family of components? This could be done so much better.
It would also be wise to move away from the Jet Database format. (.mdb files)
https://msdn.microsoft.com/en-us/library/ms810810.aspx
Instead of Microsoft Jet, Microsoft recommends using Microsoft SQL Server Express Edition or Microsoft SQL Server Compact Editionwhen developing new, non-Microsoft Access applications requiring a relational data store. These new or converted Jet applications can continue to use Jet with the intention of using Microsoft Office 2003 and earlier files (.mdb and .xls) for non-primary data storage. However, for these applications, you should plan to migrate from Jet to the 2007 Office System Driver. You can download the 2007 Office System Driver, which allows you to read from and write to pre-existing files in either Office 2003 (.mdb and .xls) or the Office 2007 (*.accdb, *.xlsm, *.xlsx and *.xlsb) file formats.
Using the newer SQL Express / LocalDB would make the catalog functions faster when combined with the database normalization. You could also allow for other database engines such as MySQL or PostgreSQL.
