IDEC WindSRV - Manual (Page 84)

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2. In this example, Linear Scaling has been selected. The raw value range allows users to specify what they expect to
receive as a data range from the actual device. The scaled data type also allows users to specify how the resulting
scaled value is presented to the OPC client application. The scaled value range is used to specify the desired range in
engineering units for the resulting value. By applying the high and low clamps, users can ensure that their output will
always stay within the configured limits. This may not always be the case. If the raw data exceeds the range set by the
raw value High and Low, it forces the scaled value beyond the range that has been entered for the scaled value. The
clamps prevent this from occurring.
3. The Units field allows users to provide a string to the OPC client that describes the format or unit for the resulting
engineering value. In order to use the Units field, an OPC client that can access the Data Access 2.0 tag properties data
is required. If the client does not support these features, there is no need to configure the Units field.
4. Once the data has been entered as shown above, click OK or Apply to commit the scaling changes.
Dynamic Addressing
Dynamic Tag Addressing is the second method for defining tags. Dynamic tags are used to define tags solely in the
client application. Instead of creating a tag item in the client that addresses another tag item created in the server,
users only need to create tag items in the client that directly accesses the device driver's addresses. On client connect,
the server will create a virtual tag for that location and start scanning for data automatically.
Note: If the data type is omitted, the driver will choose a default data type based on the device and address being
referenced. The default data types for all locations are documented in the individual driver help documentation. If the
data type specified is not valid for the device location, the server will not accept the tag and an error will be posted in
the Event Log window.
Saving the Project
If each step in this example has been followed correctly, there should now be a project configured with two user-
defined tags that are ready to be saved. How the project is saved varies and depends on whether a Runtime project
or an offline project is being edited.
When editing projects in the Runtime, the server's online full-time operation allows tags to be accessed immediately
from an OPC client once it has been saved to disk. The changes are made to the actual project, so users save by