Product specifications

SPlus Operations P13 Connectivity Guide PROCONTROL P13 OPC SERVER
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Many OPC clients do not support the data access to OPC item properties, i.e. the access via OPC items is often the
only way to get data into an OPC client. It is therefore essential to know which data an OPC server exposes through
OPC Items and possibly which through Item properties.
The PServer provides data for process variables as also for raw Procontrol data (data words).
         
data (e.g. Description text) as OPC items.
Figure 3-25: Conceptual View on Data exposed by PServer
OPC Data Access 2.0 defines an interface, GetItemProperties, which allows to read data from a server which is not
exposed as OPC items but as OPC properties.
Figure 3-26: Item Properties for a DI shown in an OPC Client
3.4.1.1 Naming Conventions for OPC Items

<Object>_<Part>.<Property>
Part and property level are optional. This means that it gives object-, part- and property-level OPC items.
Note
As every OPC item has value, quality and timestamp also every of the above mentioned types have these standard
OPC attributes.
Control System Database
Process Image Database
OPCItems
Value of
PVs
PV
Properties
Procontrol Data Words
DataWord
Value of
AI, DI etc
e.g.
Range values
Description etc.
OPC Clients