Echelon OpenLNS - Manual (Page 282)

OpenLNS Programmer's Reference 245
MinValue
Summary Contains the minimum value that can be applied to the
FormattedValue property of the DataPoint object.
•
If the data point’s source object is a network variable, the
default value for this property is determined based on the
network variable’s type, meaning that the default value
will be the maximum value supported by the type. This
value may be overridden by the network variable's entry
in the Functional Profile Template used by the device
hosting the network variable.
• If the data point’s source object is a network variable
monitor point, the default value for this property is
determined based on the source object’s type (i.e. the type
of the network variable being monitored). Note that the
override value from the network variable’s entry in the
Functional Profile Template used by the device hosting
the network variable is not available if the data point’s
source object is a network variable monitor point.
• If the data point’s source object is a configuration
property, the default value for this property is taken from
the type definitions of the configuration property type
used by the source configuration property, from the
configuration property’s entry in the Functional Profile
Template used by the device hosting the configuration
property, or from the device’s configuration property
definition file.
If OpenLNS is unable to retrieve a default maximum value
for the data point, this property will be set to
lcaRangeValueNotSet .
Note: OpenLNS will only enforce the range established by
this property when you write to the FormattedValue property
of a data point. OpenLNS will not enforce this range when
you write to the Value and RawValue properties of a data
point. As a result, you should program your application to
enforce this range for the Value and RawValue properties,
and therefore avoid writing invalid data to the data point.
In addition, the data stored in the MinValue property is not
unit-converted as is the data stored in the FormattedValue
property. Instead, the data stored in the MinValue property
is scaled data that has not been unit-converted (similar to the
data stored in the Value property). As a result, you need to
consider the unit conversions applied by the OpenLNS Object
Server when you write to the FormattedValue property to
avoid violating the range established for the data point.
You can determine what unit conversions are applied to a
particular data point by reading the UnitsMultiplier and
UnitsAdder properties of the FormatSpec object the data
point is using.