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7 result(s) for DataItems

• OPC-10000-8 – OPC Unified Architecture - Part 8: Data Access
  4 Concepts
  transparent access to their automation data. The links to automation data instances are called DataItems . Which categories of automation data are provided is completely vendor-specific. Figure 1 illustrates ... AddressSpace of a Server can contain a broad range of different DataItems . Figure 1 - OPC DataItems are linked to automation data Clients can read or write DataItems , or monitor them
• OPC-10000-8 – OPC Unified Architecture - Part 8: Data Access
  5.1 General
  Each of these VariableTypes can be further extended to form domain or server specific DataItems . Figure 2 - DataItem VariableType hierarchy
• OPC-10000-8 – OPC Unified Architecture - Part 8: Data Access
  5.3.4.1 General
  content of the array represents a single entity like an image. Other DataItems can contain arrays that represent for example several values of several temperature sensors of a boiler. ArrayItemType
• OPC-10000-8 – OPC Unified Architecture - Part 8: Data Access
  5.4 Address Space model
  Address Space model DataItems are always defined as data components of other Nodes in the AddressSpace . They are never defined by themselves. A simple example of a container for DataItems ... AddressSpace model of a DataItem , in this case an AnalogItem . Figure 4 - Representation of DataItems in the AddressSpace Each DataItem is represented by a DataVariable with a specific
• OPC-10000-8 – OPC Unified Architecture - Part 8: Data Access
  5.5 Attributes of DataItems
  Attributes of DataItems The following Attribute s of Variable s (specified in detail in OPC 10000-3 ) are particularly important for DataItems : Value DataType AccessLevel MinimumSamplingInterval Value is the most
• OPC-10000-8 – OPC Unified Architecture - Part 8: Data Access
  7.1 General
  purpose of DataAccess are: The View service set and Query service set to detect DataItems , and their Properties . The Attribute service set to read or write Attributes and in particular ... value Attribute . The MonitoredItem and Subscription service set to set up monitoring of DataItems and to receive data change notifications
• OPC-10000-8 – OPC Unified Architecture - Part 8: Data Access
  7.3.3 LimitBits
  information, but do not affect the meaning of the StatusCode . Of particular interest for DataItems is the LimitBits field. In some cases, such as sensor failure it can provide useful