constant

The constant element defines a data item with a constant value that will be published to RMDS by the adapter.

Summary

adapter                       (required, limit one)
  |----rfa                               (required, limit one)
  '----subscriptions                     (required, limit one)
         '----subscription               (required)
                '----stream              (required)
                       |----name         (required, limit one)
                       |----stale        (optional)
                       |----field        (required)
                       '----constant     (optional)

Parent

stream

Children

None

Attributes

Name	Description	Requirement
name	The name associated with this data item in the image published by the adapter	Required
value	The value of this constant (always the same whenever this data item is published to RMDS)	Required

Notes

On start-up, the adapter publishes a complete image to RMDS, containing all data items defined in the map file. After that, the adapter publishes updated values for data items only when they change, unless Event Stream Processor goes stale and then recovers. This means that the value for constant is published only when a complete image is published.

Example

<stream name="stream1" >
        <name column="0"/>
        <stale column="3" name="ACVOL_1"/>
        <field column="1" name="DSPLY_NAME" />
        <field column="4" name="BID" precision="47" />
        <field column="5" name="ASK" precision="0" />
        <field column="6" name="TRDPRC_1"/>
        <field column="7" name="ACVOL_1"/>
        <constant name="PROD_PERM" value="1"/>
</stream>

This example defines a constant called PROD_PERM, with the constant value 1, to be published with data values from stream1 under the publication name subscription1.