- Ultra-precise swivelling stick units, as used in the PROFI TX
- Aluminium sticks and aluminium 3D digi-adjuster
- Real-time on-screen telemetry displays
- MSB / SRXL technology for digital BUS integration of sensors and servos
- Wireless speech output via optional Souffleur
- Highly refined, ergonomically efficient case design (900 g)
- Integral hinged screen
- Free software updates
M-LINK is a new radio transmission system from MULTIPLEX. It operates on the 2.4 GHz ISM band, and is based on modern Frequency Hopping Spread Spectrum technology.
The features of M-LINK are as follows: Automatic RF channel management. The need for the user to change the RF channel (plug-in crystals, Synthesizer) manually is eliminated. 2.4 GHz Spread Spectrum systems divide up the frequency spectrum automatically, and for this reason conventional frequency monitoring control is no longer needed. Interference due to "channel clashes" (as is possible on the 35, 40 … MHz bands) is virtually eliminated. When the system is first used, all you have to do is "bind" the transmitter and receiver using a simple binding procedure. Once this is done, the receiver only recognises and processes the signals broadcast by its own transmitter.
Fast, accurate transmission of up to sixteen servo channels. Depending on the transmitter in use, the new MULTIPLEX M-LINK standard transmits:
- - twelve servo channels at 14 ms pulse rate
- - sixteen servo channels at 21 ms pulse rate at 12-bit resolution (3872 steps)
Feedback capability / Telemetry The 2.4 GHz ISM band provides the means of transmitting data from the model back to the transmitter. The receiver in an M-LINK system transmits the voltage of the receiver power supply to the transmitter in real time. If the voltage falls to a dangerous level, the transmitter generates a warning signal to alert the user. Additional external sensors (e.g. voltage, current, temperature) can also be connected to M-LINK receivers designed for this facility.
Diversity and dual-receiver operation
MULTIPLEX M-LINK DR (Dual Receiver) receivers are of very sophisticated construction, and feature two complete receiving circuits in one case (receiver diversity). Both circuits receive constantly, and the circuit compares the signal quality; at any one time the better signal is selected for further processing, and is passed on to the servo outputs with zero delay. If reception conditions are critical, and / or the model is particularly valuable, two receivers can be coupled together in the model; this minimises signal reflections and polarisation effects which are typical of 2.4 GHz, and represents the highest possible level of security.
Frequency Hopping Spread Spectrum technology (FHSS)
The transmitter and receiver jump (hop) from channel to channel at the same rhythm, at intervals of just a few milli-seconds. The control data is actually transmitted during a fraction of this time. It is this brief period of occupation of each channel which minimises signal conflicts and suppresses interference. Even if individual data packets are lost on individual channels, the constant high-speed process of hopping from channel to channel renders the interruption invisible to the pilot.
The MULTIPLEX M-LINK system exploits the Frequency Hopping Spread Spectrum (FHSS) process. The radiated power approved for this system is 100mW EIRP, and in practice this results in radio range of more than 2000 m on the ground. In the air the effective range is even higher due to the more favourable propagation conditions. In simple terms this means an ample margin of safety, even for large-scale models.
High data 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 2.4 GHz = 83.5 MHz; 35 MHz = 1 MHz). Digital modulation in conjunction with sophisticated error-checking and correction in the receiver ensure excellent data quality.
High resistance to interference
Typical interference sources in the model, such as electric motors, electronic devices such as speed controllers, ignition units for internal combustion engines etc., generate interference over a spectrum whose maximum frequency is far below the 2.4 GHz range. This simply means that 2.4 GHz systems are virtually immune to interference from these sources, and this results in a further improvement in safety.
HOLD / FAIL-SAFE function
If the receiver detects data which has suffered interference and is irreparable, it passes on the last valid data to the servos, thereby bridging the period of the signal loss (HOLD mode). If interference continues beyond the (variable) HOLD period, FAIL-SAFE is activated, i.e. the receiver moves the servos to a programmable safety position (e.g. throttle off, control surfaces neutral). The FS positions are stored using a push-button at the receiver; some transmitters include a menu for this, enabling the Fail-Safe positions to be set "by radio".
Short transmitter / receiver aerials
The typically short 2.4 GHz transmitter aerials are more robust and easier to handle than conventional telescopic aerials, and they also do not interfere with the pilot's field of view. Short receiver aerials are much easier to install in the model.
High vibration resistance
Small, modern, highly integrated transceiver ICs replace ceramic components, coils and filters, all of which are susceptible to damage from vibration.
Ready for LiPo
All MULTIPLEX M-LINK receivers feature a wide operating voltage range of 3.5 - 9.0 V, and are therefore largely immune to collapses in the power supply voltage. They are prepared for use with 2S LiXX batteries without voltage stabilisation to (typically) 6.0 V.
Apparatus operating on the 2.4 GHz band can be used world-wide. The components of the MULTIPLEX M-LINK system fulfil all current directives and statutory requirements.
All transmitters and receivers are equipped with modern Flash memory micro-controller technology, and can therefore be updated at any time. This means that system components can be brought up to the latest state of software development when technical innovations are introduced in the future, or when changes are made to regulations
ROYALpro with M-LINK 2,4-GHz-Technology
The ROYALpro is the radio control system for the demanding hobby pilot and expert alike, and this set can now also be purchased with the new MULTIPLEX M-LINK 2.4 GHz transmission technology. The following variants are available: ROYALpro 7 7-channel version, 15 model memories ROYALpro 9 9-channel version, 20 model memories ROYALpro 16 16-channel version, 36 model memories With the exception of the number of channels and model memories, all three variants offer the same familiar facilities and features adopted from the ROYALpro:
- Comprehensive set-up and mixer facilities for fixed-wing model aircraft and helicopters
- Various model templates for fixed-wing model aircraft and helicopters minimise the programming effort required
- Unrestricted function assignments for transmitter controls, switches and servos
- Up to four flight phases per model, with phase-specific trims
- Three timers, supplementary model / transmitter operating timers
- Five function buttons and two 3-D digi-adjusters for simple, user-friendly programming
- Six menu buttons for direct access to the main menus
- Plain text menu system in several national languages (DE, EN, FR, IT, ES)
- Ergonomically optimised case design suitable for transmitter trays and hand-held use
- Large, graphics-capable folding screen
- Cruciform trim buttons provide digital trims, specific to each flight phase
- MULTIPLEX multi-function socket fitted as standard (transmitter battery charge socket, Trainer socket, PC interface for firmware updates, data management and simulator operation) A detailed description and overview of the characteristics and features of the ROYALpro can be found in our current main catalogue, in the special ROYALpro brochure, or on our website at www.multiplex-rc.de.
The new, additional advantages are as follows:
Fully integrated M-LINK 2.4 GHz transmission technology
The new M-LINK 2.4 GHz transmission technology is integrated into the transmitter without spoiling its elegant appearance. A menu is provided as an easy and convenient means of activating the special operating modes of Binding and Power Reduction (for range-checking). This eliminates the need to operate inaccessible buttons or interpret complicated LED codes. The FAIL-SAFE positions in the receiver can also be set from the transmitter using a dedicated menu.
One special feature of the ROYALpro 16 with the HFM4 M-LINK 2.4 GHz RF module is its ability to transmit sixteen fully proportional channels, i.e. it provides four auxiliary channels. These always operate with full servo travel, and are intended for supplementary working systems in the model. If you wish to exploit these additional channels you must use the RX-16-DR pro M-LINK 16-channel receiver.
Feedback channel / Telemetry
If you use a receiver with telemetry facilities (min. RX-7-DR M-LINK or RX-9-DR M-LINK), the actual voltage of the receiver power supply is displayed on the transmitter screen. If the voltage falls below a (variable) minimum value, an audible warning signal alerts you that your receiver battery is almost flat. This means that you are constantly aware of the state of the receiver battery, as well as the condition of the transmitter battery (as previously). An important extra safety feature!
You can also set up an on-screen display of supplementary telemetry data from the model (this requires sensors connected to the receiver, e.g. voltage, current, temperature). Typical applications: motor temperature, flight battery voltage, motor current drain. See page 21 for details of telemetry sensors.
Low latency, high resolution
The ROYALevo and pro have always featured a digital RF module interface. Unlike many other 2.4 GHz transmitters or retro-fit modular solutions, this means that the data does not have to be converted from conventional PPM or PCM format to the digital 2.4 GHz transmission format. The net result is that the system is capable of transmitting highresolution, accurate control signals at very high speed. The ROYALpro with M-LINK operates with a servo pulse rate of 14 ms in twelve-channel mode (21 ms in sixteen-channel mode) and 12-bit resolution (3872 steps).
If you wish to continue using your existing stock of receivers (PPM, M-PCM) utilising conventional FM technology, you will be interested in the quick-convert facility. It is possible to convert the transmitter at the flying field in less than one minute. All you have to do is remove the HFM4 M-LINK 2.4 GHz RF module from the transmitter, withdraw the 2.4 GHz aerial from the aerial sleeve, and fit a conventional FM RF module and long telescopic transmitter aerial instead.
A retro-fit option is available for existing ROYALevo and ROYALpro transmitters utilising conventional FM transmission technology
- 1 ROYALpro 7 transmitter
- 1 HFM4 M-LINK 2.4 GHz RF module
- 1 PERMABATT+ 6 / 2100mAh NiMH transmitter battery
- 1 RX-7-DR M-LINK 2.4 GHz receiver
Transmitter Technical Specifications
Weights & Dimensions
|Weight with Battery||900g||31.75oz|
|Power Source||6 cells / 2100 mAh / NiMH / Permabatt+|