Often, a port will fail to download because a module or modules is not downloaded. Use the Event Viewer to isolate parameters that failed to download. Open the Event Viewer (click ) and in the Desc 2 column of the event grid look for the block and parameter associated with Attribute Override Failure.
Also, in DeltaV Explorer check for blue triangles
on modules assigned to
controllers. A blue triangle indicates an item that needs downloading. Modules
with extended blocks, (a DeltaV function block that communicates with a
function block running in a fieldbus device) must be downloaded before the port
to which the device is connected is downloaded.