B) Operation In The 4-Channel Mode - Conrad Electronic FS20 S4 Operating Instructions Manual

b) Operation in the 4-channel mode

In 4-channel operation each of the 4 buttons on the hand-held transmitter
has its own channel (compare with the figure in section 7):
1
Channel 1
2
Channel 2
For this reason operation is different than in the 2-channel mode. However,
switching and dimming functions are still available in 4-channel operation.
Proceed as follows:
• Switching
Pressing a button briefly (for fewer than 0.4 seconds) sends a switching
command.
The addressed receiver changes its switch state from OFF to ON or ON
to OFF, depending on which switch state was previously active.
• Dimming
If a button is pressed for longer then 0.4 seconds, a corresponding dim
up or dim down command is sent until the button is released (lamp is
dimmed up to the maximum and then dimmed down to the minimum,
and so on).
Here too, the dimming proceeds in the direction opposite to that of the
previously sent command, that is, if dim up was the last command, then
the next time the button is pressed a dim down command is sent.

The control indicator/LED (A) briefly lights up to signal that a
command has been transmitted.
14
3
Channel 3
4
Channel 4