ANSI C Based OPC UA Client/Server SDK
1.8.0.369
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Reads values and attributes asynchronously from OPC server. More...
#include <opcua_types.h>
Data Fields | |
OpcUa_Double | MaxAge |
Maximum age of the value to be read in milliseconds. More... | |
OpcUa_TimestampsToReturn | TimestampsToReturn |
An enumeration that specifies the Timestamps to be returned for each requested Variable Value Attribute. More... | |
OpcUa_ReadValueId * | NodesToRead |
List of Nodes and their Attributes to read. More... | |
Reads values and attributes asynchronously from OPC server.
The Read Service is used to read one or more attributes of one or more nodes. It allows also reading subsets or single elements of array values and to define a valid age of values to be returned to reduce the need for device reads. Like most other services, the read is optimized for bulk read operations and not for reading single Attribute values. Typically all Node Attributes are readable. For the Value Attribute the Read rights are indicated by the AccessLevel and UserAccessLevel Attribute of the Variable.