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Appendix B
Troubleshooting and Common Questions
NI-FBUS Hardware and Software User Manual
B-16
ni.com
An OPC client utility is provided with the NI-FBUS software to let you
browse Fieldbus OPC tags. Follow the instructions listed in the
section of Chapter 4,
, to
make the OPC server operational.
OPC Data Type Mapping Rule
The
SIMPLE
type and
ARRAY
type variables are regarded as leaf nodes
in the OPC address space. The
RECORD
type variables are regarded as
branch nodes, you need to access each of its member variable through this
branch node.
Table B-7 shows the data type-mapping rule.
Table B-7.
OPC Data Type Mapping Rule
Meta Type
FMS Standard
Data Types
OPC Data Type
Simple
Boolean
VT_BOOL
Integer8
VT_I1
Integer16
VT_I2
Integer32
VT_I4
Unsigned8
VT_UI1
Unsigned16
VT_UI2
Unsigned32
VT_UI4
Floating Point
VT_R4
Visible String
VT_BSTR
Octet String
VT_ARRAY | VT_UI1
Date
VT_DATE
Time of Day
VT_DATE
Time Difference
VT_DATE
Bit String
VT_ARRAY | VT_UI1
Time Value
VT_DATE