Here are a series of documents that discuss what options are available to you when considering migrating a legacy system to our current products (based on a Unity platform).
The right services at the right phase> Upgrade your Modicon Compact 984 PLC
> Upgrade to Modicon PLC while retaining your 984 ladder logic programming
> Modicon 584 migration
> SY/Max (Model 200 to 600) Migration
> TSX (47 to 107) Migration