User Manual

Logical I/O blocks
Input blocks
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256 | 351 CM110664en_07
Pulse converter (pulse counter)
The pulse converter object cumulates pulses for a meter. The Pulse converter object is used where meter
values already manipulate in a meter object or where changes of values are required to further process
control programs. Applications include: Establishing 24-hour/7-day/monthly meters, transmission by the
minute of meter values to peak load programs, etc. Precision and round off error based on real arithmetic is
possible.
Specific properties
The counter value is scaled as a REAL number directly in the object using the scaling factor. COV forming
the Present_Value can be value or time-related and a timestamp with the logged time is always provided
with the Present_Value. Reduction of Present_Value by a value (subtraction) is supported as a standard.
You can set it to a pre-defined value using a trigger function (proprietary expansion).
The Pulse Converter object can be used in two different manners: Counting or metering. The type of
application is parameterized using the FnctMod parameter.
The referenced object, e.g., an external device provides the pulse value:
● Present_Value for the pulse converter object represent the pulse count of the referenced object: The
difference to the last read value is added for each record.
● Present_Value can be set via the system.
● After start-up, the pulse converter object encompasses the last stored counter value:
● After a change in counter, the pulse converter object encompasses a false counter value.
● Typical application: On-board I/O with pulse logging.
The referenced object, e.g., an external device provides the absolute pulse value:
● Present_Value from the pulse converter object represents the absolute counter value of the referenced
object.
● Under no circumstance may the Present_Value be set via the system.
● After start-up or a change in counter, the pulse converter object after includes the correct counter
value.
● Typical applications:
– Access to an accumulator or pulse converter object is another BACnet device
– I/O Open module or M-bus with counter value integration
– Integration of a device via LON
● Incorrect applications: I/O module with pulse recording
Accumulator object (counter value)
The accumulator object can map counter states unchanged and free of errors due to rounding off or add
the counter pulse without loss and scale the same. The accumulator object is suitable to displaying meter
values that justify monetary performance. For this type of counter values, manipulations such as monthly
values, etc., must never be made directly in the meter object.
The addition of counter pulses and scaling without loss is accomplished using whole-number operations
with residual value processing. The conversion of physical pulses can be adapted using a presale
parameter. The resulting Present_Value is a scalable variable.
Present_Value depends on the function mode to synchronized adjustable to any value using a physical
meter with the last value prior to setting saved with a date/time stamp.