WEATRONIC – sistemul radio pentru cei care-si iubesc aeromodelele
Technology of the radio link weatronic 2.4 Dual FHSS
The Weatronic development team had safety in their minds as the main goal to utilize the most possible from the spread spectrum technology. There were no easily applicable components available which led to a totally newly designed system.
Radio link description
The Weatronic 2.4 Dual FHSS RC-system is a proprietary development of the Weatronic Company. The transmission of the signals is performed in the micro wave range in the 2.4 GHz-ISM-Band. For users who do not intend to acquire an individual license for every system, rules have been established. These rules have been established by the ETSI (European Telecommunications Standards Institute) and the US FCC. These rules were established to create telecommunication standards for all manufacturers and users.
For being able to utilize the maximum allowed transmission power of 100mW EIRP, the rules in Europe mandate the use of the so called FHSS. (Frequency Hopping Spread Spectrum) Weatronic uses 81 distinct frequencies with a channel width of 1 KHz each. Transmitter and receiver are hopping on these 81 channels at a rate of 100 jumps / second in a pseudo-random sequence. The algorithm (succession order of channels visited) is known only to the transmitter and the bound receiver. Disturbed channels are being avoided until available again. This is called an adaptive FHSS. This allows more systems to be operated next to each other.
- The transmitter works with a transceiver module and receives with both antennas
- The receiver has two complete receiver units with their own individual antenna.
- In addition to the transmission from the transmitter to the receiver- a return signal gets sent back from the receiver to the transmitter. (true live feedback)
The transmitter antennas are so called polar (surface) antennas, as they are being used in GPS systems or cell phones. They have a big advantage. Because of their circular polarization, the characteristic transmission pattern is close to being ideal. They are far superior to the commonly used linear polarized W-LAN rod antennas.
Circular polarized antennas create a more stable link, if obstacles intrude into the path of the link. Obstacles absorb some of the signals depending on the materials in different polarization planes, so that signals from polarized antennas are less likely to be absorbed and with that provide a safer link.
The weatronic transmission system is almost totally immune to the position of the transmitter towards the receiver, thus also providing the best receiving strength of signals by the receivers due to their insensitivity of orientation towards the transmitter.
The Weatronic makes the pilot almost independent from his or her transmitter position towards the model. It also at the same time allows the receiver to have maximal field strengths independent from its flight position towards the transmitter.
The transmitted data are being coded, so that only the receiver that has the same data code key is able to decode the signals for the servos. Several million codes are available. Multiple occupation of as on single frequency systems of 35/72 MHz is not possible. Up to 120 Weatronic systems can run parallel without fear of interference. 35/72 MHz systems can operate parallel without interference.
The Weatronic 2.4 Dual FHSS-RC system utilizes a strong return channel with all receivers, returning all data from the receiver as well as additionally optional future telemetry and sensor data. Current standard data return is
- Receiver field strength (Used for range warning)
- Receiver battery voltage (Voltage warning)
- Receiver temperature
which are being transmitted back and when triggering a limit value will illuminate the middle red transmitter module “ERROR” light, as well as sending an acoustic signal to the ear phone jack. With support of the software GigaControl other data can be used to trigger the error light together with warning signals to the ear phone jack. All receiver data also gets transmitted to back to the transmitter module and recorded on the Micro SD card. The data can also be shown as a live stream to a computer connected to the transmitter module.
The Weatronic transmitter modules have been adapted to the most common systems as Futaba, JR/Graupner and Multiplex that have frequency modules. Currently 12 channels is the maximum no of channels. (provisions for 16 channels have also been made.
Modules for the following transmitters are currently available:
- Futaba T12 FG/T14 MZ/FX-30/FX-40
- Futaba FF 7/FF 9/FF 10/WZ-2/FC-18/FC-28
- Multiplex Royal Evo/Royal Pro/Profi MC 3010/3030/4000
- Graupner MC19/MC 22/MC 22S
- Graupner MX 22/MC 24/JR 9X/JR 10X
- Graupner MX 24S
This list will be amended as transmitters are being evaluated and qualified.
|Technical specifications 2.4 GHz systems|
|Transmitter module 2.4 Dual FHSS 12 channels
Dual Receiver 2.4 Dual FHSS Micro8/10/12
Dual Receiver 2.4 Dual FHSS 12-22 R
two two cells Lithium-Polymer batteries or two three cells A123 batteries
* Quadrature Phase shift keying
System requirements of the PC for the operation software:
Processor: Intel Pentium® 4, min. 1 GHz