Multiplex HFMx V2 M-LINK Notice D'utilisation page 12

5. T M-LINK T
HE
M-LINK is a transmission system designed by MULTIPLEX. It
operates on the 2.4 GHz ISM band, and exploits modern FHSS
technology (FHSS = Frequency Hopping Spread Spectrum).
Automatic RF channel management:
With this system it is no longer necessary for the operator to
select the RF channel manually (plug-in crystals, Synthesizer).
2.4 GHz Spread Spectrum systems automatically divide up the
frequency spectrum, and this eliminates the need for conven-
tional frequency monitoring. Same-channel interference (as is
possible on the 35, 40 ... MHz band) is virtually impossible. The
first time the system is used you just have to carry out a simple
binding procedure to link the transmitter to the receiver. From
this moment on the receiver only responds to the signals from
your specific transmitter.
FHSS technology:
The transmitter and receiver jump from channel to channel every
few milliseconds, maintaining the same rhythm; the data is
transmitted during a fraction of this period. The resultant brief
period of channel occupation minimises signal conflicts, and
suppresses interference. Even if data packets are lost on par-
ticular channels, the constant high-speed hopping to the next
channel makes any interruptions unnoticeable to the pilot.
Good data security / transmission security:
The enormous bandwidth available on 2.4 GHz makes it pos-
sible to transmit much greater quantities of data than is possible,
for example on the 35 MHz band. Digital modulation in con-
junction with sophisticated error-checking in the receiver guaran-
tee outstanding data quality.
Good resistance to interference:
Typical interference sources in the model, such as electric
motors, and electronic devices such as speed controllers, petrol
engine ignition systems etc., have an interference spectrum
whose maximum frequency is significantly below the 2.4 GHz
range. It is virtually impossible for 2.4 GHz systems to suffer
interference from such sources, and this provides a further im-
provement in security.
Fast, accurate transmission:
MULTIPLEX M-LINK is a digital transmission system offering a
maximum of sixteen servo channels with a resolution of 12 bits
(3872 steps). Background noise has no effect on servo signal
accuracy right up to the limits of range. Resolution, centring
precision and with it general accuracy of control are at a con-
stant high level up to the effective limits of range. M-LINK's
digital encoding allows both HOLD and FAIL-SAFE to operate
very accurately. The servo pulse rate of 21 ms (16-channel mode)
can be reduced to 14 ms (12-channel mode - Fast Response).
Feedback capability / Telemetry:
The 2.4 GHz ISM band offers the possibility of transmitting data
from the model back to the transmitter. If you use a telemetry-
capable receiver, the transmitter emits an audible signal to warn
you when the receiver battery is almost flat. If you also install the
MULTIPLEX Telemetry-Display (# 4 5182), the screen shows
you the connection quality (LQI = Link Quality Indication) in
addition to the actual voltage of the receiver power supply. The
Telemetry-Display can also output additional telemetry data,
such as current, voltage, altitude or speed values - depending
on the sensors connected to the system. The Telemetry-Display
is capable of displaying a maximum of sixteen telemetry values.
Visual and audible warnings are generated via the Telemetry-
Display; the warning sounds are produced either by an integral
loudspeaker with volume control, or by an earpiece, which is an
optional accessory. The same applies to the Vario sound output.
Operating Instructions
HFMx V2 M-LINK 2.4 GHz RF Module
S
RANSMISSION YSTEM
Short transmitter aerial:
The short 2.4 GHz transmitter aerial is robust and easy to handle,
and it does not impinge on the pilot's field of vision.
6. I
NSTALLING THE
HFM V2 M-LINK 2.4 GH
X
6.1.: Determining the optimum location for the
HFMx V2 M-LINK 2.4 GHz RF module
If you use a hand-held transmitter, the new RF module can be
attached directly to the transmitter case. If you prefer to use the
transmitter in a transmitter tray, the HFMx V2 M-LINK 2.4 GHz
RF module can also be installed in or on the tray.
Please note the following when deciding on the location:
•
The RF module should be mounted in such a way that the
2.4 GHz aerial is as far forward as possible (towards the top
face of the transmitter). The 2.4 GHz aerial must not be
hidden by the transmitter or the Telemetry-Display. Ensure
that the aerial has an "unobstructed view" of the model.
•
When the HFMx V2 M-LINK 2.4 GHz RF module is installed,
it must be possible to rotate and tilt the aerial attached to the
module to ensure that the radiation pattern is as good as
possible ( 11.).
•
It must be possible to connect the DIN plug attached to the
RF module to the transmitter's Trainer socket when the mo-
dule is in place (check cable length!).
•
Ensure that the components of the RF module (case, aerial,
lead and plug) do not obstruct access to the transmitter's
switches, sliders and rotary controls, nor prevent the pilot
reading the transmitter screen.
•
If you wish to attach the RF module to the back of the trans-
mitter, if at all possible position it in the area protected by a
transport handle, to avoid the risk of mechanical stress on
the module when the transmitter is put down.
6.2.: Securing the HFMx V2 M-LINK 2.4 GHz RF module
Our example illustrates the method of fixing the HFMx V2
M-LINK 2.4 GHz RF module to the case of a PROFImc 4000
transmitter (used hand-held). The same basic method can be
used to attach the RF module to or in a transmitter tray, or to a
different type of transmitter.
1. Stick the Velcro tape (loop side) to the recessed areas on the
back of the RF module:
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RF M
Z ODULE