User manual

IEC61131 User and Reference Manual
April 22, 2008
520
16-Bit Analog Inputs parameters are set in this property page. Each parameter is described in the
following paragraphs.
The Number of Points displays the number of 16 bit analog inputs reported by the RTU. This value
will increment with the addition of each configured 16-Bit Analog Input point. The maximum
number of points is 9999. The maximum number of actual points will depend on the memory
available in the controller.
The Starting Address parameter specifies the DNP address of the first 16-bit Analog Input point.
The Event Reporting Method selection specifies how 16-bit Analog Input events are reported. A
Change Of State event is an event object, without time, that is generated when the point changes
state. Only one event is retained in the buffer for each point. If a subsequent event occurs for a point,
the previous event object will be overwritten. The main purpose of this mode is to allow a master
station to efficiently poll for changed data. A Log All Events event object with absolute time will be
generated when the point changes state. All events will be retained. The main purpose of this mode is
to allow a master station to obtain a complete historical data log. The selections are:
 Change of State
 Log All Events
The Event Buffer Size parameter specifies the maximum number of 16-Bit Analog Input change
events buffered by the RTU. The buffer holds all 16-Bit Analog Input events, regardless of the class
to which they are assigned. If the buffer is completely full the RTU will lose the oldest events and
retain the newest; the ‘Event Buffer Overflowed’ IIN flag will also be set to indicate that the buffer
has overflowed. The Event Buffer size should be at least equivalent to the number of 16-Bit Analog
Inputs defined as Change of State type. That will allow all 16-Bit Analog Inputs to exceed the
deadband simultaneously without losing any events. The value of this parameter is dependent on
how often 16-Bit Analog Input events occur and the rate at which the events are reported to the
master station. The valid values for this parameter are 0 - 65535. Default value is 16.