Art. No. SC 1000 KNX
The parameter "Interpretation object fan control automatic/manual" in the fan control parameter
group defines with which switching value the automatic or manual operation is set via the
communication object. Automatic mode is always active after a device reset.
i
The "Ventilation, auto/manual" object transmits actively ("Transmit" flag set). When the
operating mode is changed over using local control, the valid status is transmitted to the
bus.
i
Updates to the object value "Automatic mode active" -> "Automatic mode active" or
"Manual mode active" -> "Manual mode active" do not produce any reaction.
Automatic mode:
The command value of the controller is used internally in the device for automatic control of the
fan levels. As a transition between the levels, there are threshold values, defined according to
the command value of the controller, which can be set using parameters in the ETS. If the
command value exceeds the threshold value of a level, the appropriate level is activated. If the
command value sinks below a threshold value, minus the configured hysteresis, then the
change-over takes place into the next lowest fan level. The hysteresis value applies to all the
threshold values.
The threshold values for the individual fan levels can be parameterised freely in the range from
1 ... 99 %. The threshold values are not checked for plausibility in the ETS, meaning that
incorrect parameterisation is possible. For this reason, it must be ensured that the threshold
values, compared to the level value, are configured in a rising direction (level 1 threshold value
> level 2 threshold value > level 3 threshold value > etc.).
When the command value changes, and thus the fan level, it is only possible to switch directly
into neighbouring levels (exception: switch-on level). Thus, in Automatic operation, it is only
possible, for example, to switch from level 2 down to level 1 or up to level 3. If the command
value change exceeds or undershoots the threshold values of multiple fan levels, then, starting
with the current fan level, all the fan levels are activated in succession until the fan level
specified by the command value is reached.
If the fan is switched off by the automatic system, then it runs on for the time configured as "Fan
run-on time, heating" or "Fan run-on time, cooling", providing that these run-on times are
configured in the ETS.
i
In automatic mode, the fan level objects are updated according to the internal command
value calculation (cyclically every 30 seconds) plus the waiting time configured for level
change-over. Telegram transmission only takes place when the object values of the fan
levels are changed. After a device reset, the fan level objects are updated and the status
transmitted to the bus.
i
If a switch-on level is configured in the ETS ("Start-up via level" parameter), then, before
the automatic activation of a fan level, it is possible to switch to a level, specified in the ETS
and usually higher, for a brief time according to the command value (see section "Switch-
on level").
i
The command value evaluated by the fan controller in Automatic mode can be optionally
limited by in the top and bottom command value ranges by the parameters "Command
value is 0% until internal command value is greater than" and "Command value is 100% as
soon as internal command value is greater than". In addition, the command value can also
be raised by a constant value by the "Command value offset" parameter (see
page 218-219).
Manual operation:
If the controller is in automatic mode, then a long press of the display / operating element or a
command to the communication object "Ventilation, auto/manual" switches to manual mode.
The parameter "Fan level on change-over to manual" then decides whether the fan level most
recently set in automatic mode is maintained, the fan is switched off or a defined fan level is set
(see also next section "Switch-on level").
If the top sensor element
+
is pressed, the controller switches to the next-highest fan level. If the
fan is at the highest level, pressing it again has no effect.
If the fan is switched off manually from the highest level, then it runs on for the time configured
Page 215 of 347
Software "Smart Control 501511"
Functional description
