National Instruments 370578B-01 用户手册

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Glossary
© National Instruments Corporation
G-7
V
VCR
See Virtual Communication Relationship.
VFD
See Virtual Field Device.
Virtual Communication 
Relationship
Preconfigured or negotiated connections between virtual field 
devices on a network.
Virtual Field Device
The virtual field device is a model for remotely viewing data 
described in the object dictionary. The services provided by the 
Fieldbus Messaging Specification allow you to read and write 
information about the object dictionary, read and write the data 
variables described in the object dictionary, and perform other 
activities such as uploading/downloading data and invoking 
programs inside a device. A model for remotely viewing data 
described in the object dictionary.