Echelon SmartServer 2.2 - Manual (Page 263)

264 Using the SmartServer as Network Management Tool
the heartbeat of any output bound data point should be 5 seconds. This
allows for lost messages.
Use Send On
Delta This property applies to all data points. You can set the minimum amount
of change required for a data point to send an updated value to all
SmartServer applications in which the data point is a member. To set a
send on delta value for this data point, select this option and enter a value.
For example, if you set this property to 1 for a structured data point (for
example, SNVT_switch or SNVT_setting) or to a specific value for a
scalar data point, the data point will send an update to the applications
each time it changes by that value.
If this option is cleared, the SmartServer applications will use their default
send on delta values for determining when a data point is to be updated.
For example, the default send on delta value for the Web Connection
application is for updates to be sent only if the value changes. This is to
avoid instances such as a modem connection being created on every
heartbeat.
The default for all the other SmartServers 100 applications is 0, which
means that the applications receive data point updates, regardless of
whether the value changes.
Presets You can use presets to define strings that represent specific values for a
data point. Using presets enables you to integrate data points with varying
types and structures into the SmartServer applications seamlessly.
For example, you can define a preset named ON for a SNVT_switch data
point with a value of 100.0 1, and a preset named ON for a SNVT_temp_f
data point with a value of 22. You could then add these data points to a
Scheduler application and have it set both data points to ON at a specific
time. In this case, the Scheduler does not need to know that
SNVT_switch requires both a state and a value or that SNVT_temp_f
requires a floating point value. Instead, the SmartServer’s internal data
server uses the presets to translate the strings into their required types and
formats and updates the data points at the specified time. This example
also demonstrates how you can use presets to drive multiple data points
with differing types simultaneously.
To create a preset, click Add Preset. Enter the name for the new preset in
the Preset Name box and then enter a valid value in the Preset Value
box. This preset value will be applied to the data point when the specified
preset name is called. You can also click the box to the right to open the
Edit Presets dialog, where you can view the valid range of values for the
data point and enter the preset values.
To remove a preset, select it and click Delete Preset.
For presets with multiple values, you can use the arrows to re-order which
values are written to the data point when the preset name is received. For
example, consider a SNVT_switch data point that has two values for the
OFF preset (0.0 0 and 100.0 0), and the 0.0 0 value is listed before the
100.0 0 value. When the OFF preset is received, the 0.0 0 value will be
written to the data point because it is the first one listed for that preset. If
you want the 100.0 0 value to be written to the data point, click anywhere
in the Preset Name or Preset Value header and then click an arrow to
re-order the presets so that the 100.0 0 value is listed before the 0.0 0
value.