When doing development, the Design (Local) tab is used to allow your computer to talk with the PLC. This allows you to browse addresses/tags in the PLC online while you develop your application. It also allows you to test your app on your computer without having to download it to a live PV+.
However, the Design (Local) tab does not have ANYTHING to do with how the PV+ talks to the PLC. For that you must configure the Runtime (Target) tab in RSLinx Enterprise. This setting is what actually gets downloaded to the PV+. In this tab you CANNOT browse like you can in the Design (Local) tab. Think about it.....your computer cannot browse as the PV+. You either manually add the devices or you use the COPY option to copy the settings from the Design (Local) tab to the Runtime (Target) tab.
Note....in version 5 of the FactoryTalk View Studio software the Local tab was renamed to "Design" and the Target tab was renamed to "Runtime". Since you didn't mention what software/version you are using (please do so in the future to avoid the "what version are you using" that will be asked) I included references for older and newer software. The software also renamed from RSView Studio to FactoryTalk View Studio in version 5.
OG