Echelon i.LON SmartServer 2.0 User Manual
Page 123
i.LON SmartServer 2.0 Programmer’s Reference
8-5
Property Description
Input
Analog Function Block. The input data points for an
Analog Function Block are defined by a list of
elements with dpType attributes of ="Input".
For each element, you must specify an index number to be
used within the Analog Function Block (UCPTindex), the
name of the data point (UCPTpointName), and the interval
to use when polling the data point’s value (UCPTpollRate).
The poll rate must be specified as an integer between
0-6553. If the input data point is a structure, you must also
specify the name of the field to use when performing
comparisons with the data point (UCPTfieldName).
The value of the selected field for each input data point will
be used to generate a value for the output data point. This
value assigned to the output data point will vary, depending
on the output function (UCPToutputFunction) selected for
the Analog Function Block.
NOTE: You should note that other SmartServer
applications may cause the Data Server to poll this data
point’s value as well. The poll rate specified by these
applications should be compatible with each other. For
example, if an Analog Function Block is polling a data point
every 15 seconds, and the Data Logger is polling that data
point every 10 seconds, then the Data Server will have to
poll the value of the data point every five seconds to ensure
that each application gets a current value for each poll.
It is important to note this as you set poll rates for various
applications, as you may end up causing more polls than is
efficient on your network. For example, if an Analog
Function Block is polling a data point every 9 seconds and
an Alarm Generator is polling a data point every 10 seconds,
the Data Server would have to poll the data point every
second to ensure that each application polls for a current
value. This may create a significant amount of undesired
traffic.
Compare
This element defines the compare data point this Analog
Function Block will use.
You must specify the name of the data point
(UCPTpointName), the name of the field to use when
making comparisons with the data point (UCPTfieldName)
if it is a structure, and the interval to use when polling the
data point’s value (UCPTpollRate).
The value of this data point will be compared to the value of
each input data point when the output function selected for
the Analog Function Block is FN_COMPARE, FN_AND or
FN_OR. The comparison to perform is determined by the
comparison will be stored in the output data point.
This value will not be used in comparisons if the