e) Using the FS20 wireless connection
The FS20 wireless connection allows the switching signal to be used at a location a long distance for
the "FHT 8W" without the need for a cable connection.
This is of particular use if the heating system is in a room where you cannot ensure that all thermostat
signals will be received. This is made clearer by the two switching diagrams on the following page.
In the upper diagram the "FHT 8W" is directly connected to the heating system, the FS20 wireless
connection is not used. In the lower diagram the "FHT 8W" gathers data at a central location within
the house. The connection to the heating system is not carried out using the internal relay but rather
via an FS20 controlled wireless switch.
All FS20 switching actuators are suitable as receivers. these are however not controlled with a
command which continually activates the output, but with a timer command instead which will activate
the actuator for a maximum of 15 minutes.
As long as the actuated status is required, the "FHT 8W" regularly send new "activate for 15 minutes"
commands which retrigger the actuator. This guarantees that the actuator will not remain in the current
switching state for any longer than 15 minutes if the wireless signal is lost for any reason.
The menu item "FS20 Aktivieren" (= "Activate FS20") (see chapter "FS20 menu) allows you to specify,
whether the relay of the receiver is to be activated when there is heating demand ("1") or when there
is no heating demand ("2"). In the basic setting ("0") there is no transmission of FS20 commands.
The following table gives an overview of the allocations described.
Menu item
Activate FS20
1
2
32
Heating demand
Not present
Present
Not present
Present
External relay
(e.g. "FS20 AS1")
External relay
if signal lost