Echelon OpenLNS - Manual (Page 287)

OpenLNS Programmer's Reference 250
device-specific, the value will be read from
the database, as long as it is stored there.
If its value does not exist in the database,
then the value will read directly from the
device, as long as the network management
mode (MgmtMode property) is set to
lcaMgmtModePropagateConfigUpdate
s (0).
If the source ConfigProperty is not
device-specific, the value is not in the
database, and the network management
mode is set to
lcaMgmtModeDeferConfigUpdates (1),
then an exception will be thrown when you
read the value of the DataPoint.
1 lcaDataSourceOptionsFromDevice
The data point value is always matched to
the value of the source ConfigProperty in
the physical device. You can use this
information to synchronize the value of a
ConfigProperty in the OpenLNS database
with the value stored in the physical device.
To do so, read the value of a data point
created with this option set. Then, set the
SourceOptions property of the data point to
lcaDataSourceOptionsDatabaseOnly
(2), and call the Write method. The value of
the source ConfigProperty in the OpenLNS
database will then match the value of the
configuration property on the physical
device.
2
lcaDataSourceOptionsDatabaseOnly
The data point value is always read from
the OpenLNS database. When you write to
the data point, the new value will be
written to the ConfigProperty in the
OpenLNS database only, and not to the
physical device. Writing to a DataPoint
with the SourceOptions property set to this
value is recommended only when updating
the database with a value that has just
been read from the device. For more
information on this, see the description of
the lcaDataSourceOptionsFromDevice
(1) value.
If you read the value of the data point, and
the value does not exist in the OpenLNS
database, then the NS, #113
lcaErrNsCpValueNotFound exception is