Honeywell Uniformance R300, User Manual

Page: 49 / 60

5 Using the PHD OPC Server
5.4 PHD OPC Data Standards for Client Applications
Uniformance - PHD OPC Server User Guide
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5.4 PHD OPC Data Standards for Client Applications
The PHD OPC Server is compliant with the IOPCServer definition of the latest OPC Data
Access Standard. All mandatory interfaces are implemented per the standard specification;
however, not all optional interfaces are implemented.
The client application should use the QueryInterface mechanism as specified by OLE and
OPC to determine if a server supports a given interface. For all interfaces that are not
implemented, the PHD OPC Server returns the status E_NOTIMPL as specified by the
standard.
HRESULT
In order to make the return interface consistent with OPC APIs, the PHD OPC Server uses a
consistent 32-bit return value called HRESULT. Each API description includes a table of
returned HRESULT values.
PHD OPC interfaces return the following status values:
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S_OK
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E_FAIL
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E_ABORT
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OPC_E_UNKNOWNITEMID
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OPC_E_BADRIGHTS
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E_ACCESSDENIED
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E_NOTIMPL
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E_INVALIDARG
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E_UNEXPECTED
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E_NOINTERFACE
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E_POINTER
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E_OUTOFMEMORY