Chapter 3 PLC System Configuration & Settings Device Description File Manager Use the wizard to install / uninstall description files (IODD, DDF) by clicking “Device Description File Manager” on HWCONFIG tool bar under the Tool tab to open the Device Description File Manager page. Choose to install or uninstall description file and click on “Next”. 3-33 Item Description Device Description File Manager Use the wizard to install / uninstall description files (IODD, DDF). Environment Setting General: Enable prompt confirmation, retain last layout setting and manage theme style. PO List List all the compatible devices and accessories that the created project may need for your reference.