Handbuch-KnxSmartmeter-85A-en-3.odt, 2018-10-04
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φ
P
Q
positive active power =
consumption with respect
to the power count arrow
at current sensor
negative active power =
generation with respect
to the power count arrow
at current sensor
S
positive reactive power
consumed, inductive
positive active power
positive cos φ
consumed, capacitive
positive active power
positive cos φ
generated, inductive
negative active power
negative cos φ
generated, capacitive
negative active power
negative cos φ
negative reactive power
Figure 24: Representation of the counter quadrant
General Function Concepts
Cyclical transmitting
Measured values and counter readings can be transmitted cyclically on the bus. The function is
used as for equidistant representation of a measured value on the bus or in a diagram and thus
represents a sampling of the measured value.
When activated, the corresponding values are transmitted on the bus in a cycle time, which can
also be parametrized by ETS. The first transmission is carried out shortly after a restart of the
application. From this moment the value is transmitted cyclically. The transmissions are not
synchronized with day-time in this case.
If the cycle time 0 is given in the ETS, the value will never be transmitted cyclically.
Transmit at Change
Measurement values and counter readings can be transmitted on the bus after a change. The
function is used for a complete representation of a measurement on the bus or in a diagram.
Since the measured values are only transmitted after a change this can be done with a minimal
strain of the bus. On the bus a maximum of one change of a measurement value per second
can be transmitted.
In the ETS it can be parametrized, at which change the value on the bus is retransmitted. This
value is indicated in percentage. The first transmission is always performed shortly after a restart
of the application. From this point a new value is transmitted in each case, if the measured value
has changed by more than the set percentage value relative to the value last transmitted on the
bus. It is independent of whether the value last transmitted has been transmitted due to the
function “Transmit cyclically”, “Transmit at change” or “Request measured values”.
Attention:
In the setting “Transmit at change” it is to be noted that the last transmitted measured
value can vary from the actual current measurement value by up to the percentage value which
is parametrized in the ETS respectively. With the help of the adjustable percentage a suitable
compromise between the deviation of the indication from the current measured value and the
bus strain can be found.
If in the ETS the percentage is specified to 0% the value will never be transmitted on a change.
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