Chapter 5
Developing The Application
NI-FBUS Hardware and Software User Manual
5-4
ni.com
Table 5-1 shows the data type-mapping rule.
Table 5-1.
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
Array
Boolean
VT_ARRAY | VT_BOOL
Integer8
VT_ARRAY | VT_I1
Integer16
VT_ARRAY | VT_I2
Integer32
VT_ARRAY | VT_I4
Unsigned8
VT_ARRAY | VT_UI1
Unsigned16
VT_ARRAY | VT_UI2
Unsigned32
VT_ARRAY | VT_UI4
Floating Point
VT_ARRAY | VT_R4
Visible String
VT_ARRAY | VT_BSTR