Changing PD tag is not a fast operation in Foundation Fieldbus. NI-FBUS Configurator will send PD tag request to the stack, then wait for the response. Moreover, Configurator will also update all related information.
Only NI-FBUS LabVIEW VIs supports changing PD tag operation. The VI is FF_SetDeviceTag.vi.
Feilian (Vince) Shen