Echelon i.LON SmartServer 2.0 - Manual (Page 85)

i.LON SmartServer 2.0 Programmer’s Reference 6-7
Property Description
Point – lowLimit2Offset
The value entered for <UCPThighLimit2Offset> must be
greater than that entered for <UCPThighLimit1Offset>, and
the value entered for <UCPTlowLimit2Offset> must be less
than that entered for <UCPTlowLimit1Offset>. The default
value for each property is 0. If any of these properties are
left empty, they will not be used to check for alarm
conditions. When you set these properties, you must also
set the corresponding hysteresis properties
Each alarm condition caused by the offset properties will
cause the <UCPTpointStatus> of the input data and alarm
data points to be set to a different status. For more
information, see Hysteresis Levels and Offset Limits.
Note: If you use the Get function to retrieve the
configuration of an Alarm Generator whose input or
compare data points use the format type
SNVT_temp_p#US or SNVT_temp#US, then the values of
these properties will be displayed using the
SNVT_temp_f#US format. This rule applies to all formats
that use the #US specifier.
When an alarm occurs based on one of the offset limits
described above, the value of the input data point must reach
the hysteresis value for that limit before the alarm can be
cleared, and another alarm can be generated based on that
offset limit.
This allows you to set up an Alarm Generator that will
trigger an alarm once each time the value of the input data
point reaches a certain level, as opposed to multiple times
(which would occur each time the data point was updated
and its value remained within the range specified by the
offset limit).
Enter a scalar value for each of these properties. These
values define the hysteresis level that will be used for each
alarm offset limit. For a more detailed description of the
hysteresis fields and how they relate to the offset limit
values, see Hysteresis Levels and Offset Limits.
Note: If you use the Get function to retrieve the
configuration of an Alarm Generator whose input data point
uses the format type SNVT_temp_p#US or
SNVT_temp#US, then the values of these properties will be
displayed using the SNVT_temp_f#US format. This rule
applies to all formats that use the #US specifier.
Input
The input data point for this Alarm Generator. The data
point must be referenced by its .
Each time this data point is updated, its value will be
compared to the value of the compare data point using the
comparison function defined by the
property. If the result of the comparison is True, an alarm