Multiplex HFM4 M-LINK Notice D'utilisation page 9

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
possible to transmit much greater quantities of data than is
possible, for example on the 35 MHz band (bandwidth on 2.4
GHz = 83.5 MHz; on 35 MHz = 1 MHz). 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 standard servo pulse rate of 21 ms (16-
channel mode) can be reduced to 14 ms (12-channel mode -
Fast Response) in the case of the ROYALevo, ROYALpro and
ROYALpro M-LINK transmitter types.
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 actual voltage of the receiver power supply
is displayed on the transmitter's integral screen. If the voltage
falls below the set minimum value, an audible signal warns you
that the battery is almost flat. It is also possible to have
additional telemetry data from the model displayed on the
screen, provided that appropriate sensors are installed in the
model; these parameters include motor current, battery voltage,
temperature, ...).
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.
7. I
NSTALLING THE
HFM4 M-LINK 2.4 GH
The following section describes the method of installing the
HFM4 M-LINK 2.4 GHz RF module in a transmitter of the
ROYALevo, ROYALpro or ROYALpro M-LINK type.
7.1.: Open the transmitter case
! Switch the transmitter OFF before opening the case
(short-circuit hazard)!
1. Hold the transmitter in both hands, locate the sliding latches,
and push both of them down using your thumbs (in the
direction marked "OPEN"):
Operating Instructions
HFM4 M-LINK 2.4 GHz RF module
RF
Z MODULE
Page 9
2. Carefully remove the back cover of the transmitter case.
7.2.: Remove the transmitter aerial (35, 40, ... MHz
telescopic aerial)
1. Collapse the transmitter aerial and push it down towards the
transmitter battery.
2. Withdraw the aerial from the aerial guide sleeve as shown:
7.3.: Remove the installed 35, 40, ... MHz RF module
These RF modules are not protected by a case. For this reason:
Avoid touching the components on the main circuit board.
Do not place the main circuit board under mechanical strain.
Do not place the RF module under mechanical strain.
1. Lay the transmitter face-down on a soft surface. Take care to
avoid damaging the sticks and switches!
2. Grasp the RF module in the transmitter by all four corners
using your thumbs and index fingers, and carefully lift it out:
3. Store the RF module you have removed in a protective anti-
static bag.
7.4.: Plug in the HFM4 M-LINK 2.4 GHz RF module
1. Remove the HFM4 M-LINK 2.4 GHz RF module from the
protective anti-static bag, and hold it as described above.
2. Carefully insert the RF module using steady pressure.
Ensure that the module is fitted on the correct pins, and is
inserted "squarely", i.e. not canted over:
OPEN