Graupner Hendheld RC 2.4 GHz No. of channels: 12 33124 Data Sheet

Product codes
33124
Page of 296
180 Detail program description - Control adjust
  General notes on freely programmable mixers
The previous pages have described a wealth of ready-
to-use built-in coupling functions, in the context of the 
two menus "Wing mixers" and "Helicopter mixers"
The fundamental signifi cance of mixers and the principle 
by which they work are described on page 145. The 
following section presents you with information relating 
to "free mixers". 
In addition to the pre-programmed mixers previously 
mentioned, the 
mx-20 HoTT offers a number of freely 
programmable mixers in every model memory, whose 
inputs, outputs and mixer ratios can be confi gured to suit 
your exact requirements: 
8 linear mixers, numbered M1 to M8
• 
4 curve mixers, numbered K9 to K12
• 
These 12 mixers are certainly adequate for most 
applications and are invariably suffi cient when you 
incorporate the pre-programmed coupling functions 
offered. On the "Mix active/phase" menu (see page 
192), you are also free to specify which of these 
12 mixers is activated or deactivated separately for each 
fl ight phase.
For the "free mixers", the signal present at any control 
function (1 to 12) can be assigned as the input signal
For the "switch channel" (see further below), the signal 
from any switch can be utilized. The signal that is 
present at the control channel and passed to the mixer 
input is always infl uenced by its own transmitter control 
and by any control characteristic that may have been 
set, e. g. those specifi ed by the "Dual Rate / Expo", 
"Channel 1 curve" and "Control adjust" menus. 
The mixer output acts on a control channel (1 to 12, 
depending on receiver type) that can also be assigned 
freely
. Before this channel routes the signal to the servo, 
it can be infl uenced only by the  "Servo adjustments"  
menu, i.e. by the the servo reverse, neutral point offset, 
servo travel and servo travel limit functions, and also 
possibly by " Tx. output swap ".
One control function can be used for any number of mix 
inputs simultaneously: if, for example, several mixers 
should be switched to act in parallel.  
Conversely, it is possible for any number of mixers to 
affect one and the same control channel. Particularly in 
the latter case, however, it is very important to ensure 
that the servo concerned does not strike its mechanical 
end-stops when several mixer signals accumulate 
to an excessive extent. For safety's sake it may be 
worth setting an appropriate travel limit on the "Servo 
adjustments
" menu in such cases.
For more complex applications, mixers can be switched 
in sequence. In this case, it is not the (transmitter) signal 
at the "output" of a control function which forms the input 
signal of the "series-wired" mixer, but the (mixed) signal 
"further back" at the "input" of a control channel. The 
following description of the free mixers includes several 
examples of this type.
In the software, one "free mixer" is always initially 
activated. If you wish, however, the mixer can also be 
assigned an ON/OFF switch. Since there are so many 
functions to which switches can be assigned, you must 
be careful to avoid undesirable multiple assignments.
  The two key mixer parameters are: 
  … 
• 
the mixer ratio, which defi nes the extent to which 
the input signal acts on the output of the control 
channel connected to the mixer output. 
If you are using linear mixers, the mixer ratio can be 
set as symmetrical or asymmetric. Curve mixers can 
also be confi gured with up to 6 points to suit your 
application, enabling the implementation of highly 
non-linear curves.
  … 
• 
the neutral point of a mixer, which is also 
referred to as the "offset". 
The offset is the specifi c point along the travel of a 
transmitter control (joystick, CTRL 6 … 8 proportional 
controls or switches 1 … 9) at which the mixer no 
longer infl uences the control channel connected to 
its output. Normally, the neutral point is the center 
point of the transmitter control. However, the offset 
can also be set at any other point along the control 
travel. Since there are no restrictions on the design 
of the curve mixers, setting a mixer neutral point only 
makes sense for the 8 linear mixers.
  Switch channel "S" as a mixer input
Occasionally, however, only a constant control signal is 
required at the mixer input. A typical application would 
be a slightly increased "up-elevator" trim when the aero-
tow release is closed  –  fully independently of its normal 
trim  setting.   
In this case a switch is assigned both to the aero-tow 
release and the mixer; it is then used not only to open 
and close the release, but also to pass the desired trim 
signal to the elevator via the mixer ratio. To identify this 
special arrangement, this mixer input control function in 
the program is designated "S" for "Switch channel". 
In addition, if the corresponding "target channel" should 
now no longer be infl uenced by its "normal" transmitter 
control, then you should isolate the latter from the 
function input of the affected control channel on the 
"MIX-only channel" menu (page 193). In the menu 
description that follows, an example is also given to 
illustrate this function.
Using the arrow keys on the left or right touch pad, page