With NI-FieldPoint 4.0 and earlier, you can not use the FieldPoint Read/Write/Advise VI's with FieldPoint tags that are not located on the bank directly connected to the FP-20XX controller. Instead, to access tags on other ethernet network modules, you need to use DataSockets to connect to the published items. For serial modules, you need to use the FieldPoint Optomux VI's. I do not know if FieldPoint 4.0.1 has added the ability to communicate with non-local tags on RT controllers.
Regards,
Aaron
LabVIEW Champion, CLA, CPI