The function of radio gate openers and criteria for classifying the different types of device on the market.
What is a radio-controlled gate opener and how does it work?
A radio-controlled gate opener is a device that enables remote gate activation using electromagnetic waves. It operates through the interaction of two different units: a transmitter, the portable element available for the user, and a receiver in a fixed position with cable connection for control of the device.
The transmitter sends a message to the receiver by means of a radio wave transmitted at a specific frequency. The information contained in the message consists of a security code (the user code) and an activation command. The receiver, having detected the radio signal, extracts the message, compares the security code with the one already in its memory and, if the two match, it activates a relay thus executing the actuation command.
Radio gate openers can be subdivided using two criteria:
- The working frequency (expressed in Mhz)
- The code transmitted (fixed or variable)
It is now possible to classify radio controls further. By using frequency as an identification parameter, we can divide the radio controls into:
1° Quartz (that normally transmit at a low frequency: 15-41 MHz)
2° Free frequency (that normally transmit with frequencies between 200 and 360 MHz)
3° European frequency (433.92 MHz or 868,35 MHz frequency)
By using code as an identification parameter, we can divide the radio controls into two different types:
- Fixed code
- Variable code (also called Rolling Code)
A fixed code radio control always uses the same binary code for transmitting: in essence, the code sent by the transmitter is the same for each system and the receiver unit can clearly recognize it. Whenever it is necessary to duplicate such radio controls, the fixed code already used for the automation must be copied using one of the radio control’s self-learning models.
All fixed code radio controls can be duplicated without having to perform operations on the receiver unit. A functioning transmitter must be available for duplication.
On the other hand, in Variable code (also known as Rolling code) radio controls, the code generated by the transmitter is always different for every new activation, and is dependent on an algorithm established by the manufacturer. Thanks to an internal system, the receiver is always synchronized with its transmitter. This peculiarity means that not all Rolling code radio controls can be copied in self-learning mode.