User manual

IEC61131 User and Reference Manual
April 22, 2008
541
16-Bit Counter 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 Counter Inputs reported by the RTU. This
value will increment with the addition of each configured 16-Bit Counter Inputs 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 Counter Input point.
The Event Reporting Method selection specifies how 16-Bit Counter 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 is 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 Counter Input change
without time events buffered by the RTU. The buffer holds all 16-Bit Counter Input events,
regardless of the class to which they are assigned. If the buffer fills to 90 percent the RTU will send a
buffer overflow event to the master station. If the buffer is completely full the RTU will lose the
oldest events and retain the newest. 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 Counter
Inputs to exceed the threshold simultaneously without losing any events. The value of this parameter
is dependent on how often 16-Bit Counter 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.
For SCADAPack 32 and SCADAPack 32P controllers counter input events are processed by the
DNP driver at a rate of 100 events every 100 ms. If more than 100 counter input events need to be
processed they are processed sequentially in blocks of 100 until all events are processed. This allows
the processing of 1000 counter input events per second.
For SCADASense Series of controllers, SCADAPack 100, SCADAPack LP, SCADAPack and
Micro16 controllers counter input events are processed by the DNP driver at a rate of 20 events
every 100 ms. If more than 20 counter input events need to be processed they are processed
sequentially in blocks of 20 until all events are processed. This allows the processing of 200 counter
input events per second.
The Allow Duplicate Modbus Addresses checkbox determines if the Modbus I/O database
addresses assigned to the DNP data points must be unique. Check this box if you want to allow more
than one point to use the same Modbus address.