The SPI to DeltaV XML interface assumes that each signal parameter in a Device Signal Tag is used by only one function block. (Normally this is all that is required.) If a signal parameter is assigned to more than one function block, when you publish the configuration from DeltaV software, the published xml file contains information only from the first usage of the parameter found in the DeltaV configuration.
Therefore it is recommended that each signal parameter be assigned to only one function block. If a signal is required by more than one module expose it as an output parameter of the module that contains the block the signal is assigned to.