--- Monitors / controls the polarization plane.
--- The device info page.
--- The maintenance page. The configuration parameters described below are set at this page.The Polarization-Select logical device lets you derive a polarization plane information from the antenna's polarization angle value. The other way round it lets you command a polarization plane by turning the feed by 90° to the on or other direction.
The device uses a simple algorithm to determine the polarization plane from the angle: Within the possible range of polarization angle settings there is at least one threshold which separates horizontal from vertical settings. Switching the polarization is made by shifting the angle by 90° across this threshold.
By definition the polarization plane controlled by the device in this way is the receive polarization. Additionally the device provides the orthogonal setting as a read-only parameter labelled 'transmit-polarization'.
Device window pages
The following table shows which device window pages are available with this individual device type. Tool-bar functions not mentioned here are described at the general description of device windows .
--- Monitors / controls the polarization plane. --- The device info page. --- The maintenance page. The configuration parameters described below are set at this page.Configuration parameters
At the maintenance page of the device window there are a couple of configuration parameters which must be set to integrate the device into the VLC/M&C.
| parameter | description |
|---|---|
| polarizationId | The parameter ID of the polarization angle of the antenna. This must be the parameter that actually controls the angle, not the state report parameter. |
| separationMode | Selects which range of the polarization angle shall be considered as horizontal, which a vertical. 'HORIZONTAL-BELOW' treats values below the threshold as horizontal, values above as vertical. 'HORIZONTAL-ABOVE' sets the opposite sense. |
| separationValue | Sets the threshold value which separates horizontal from vertical settings. If the possible range of polarization angles covers more than 180°, then there are more than one of these separation points. In such a case, a threshold value near to the center of the possible range should be used. |
Remarks
The Polarization-Select device cannot handle 360° rollovers of the angle. This is, because then the angle - polarization plane correlation would be no more biunique, making it impossible to reconstruct the original settings after a plane switch.
For this reason you should calibrate / offset the polarization plane setting at the antenna in a way, that not 360° rollovers happen in the valid angle range.
Variables defined by this device driver
| name | type | flags | range |
|---|---|---|---|
| info.driver | TEXT | R/O | StringRange R/O |
| info.type | TEXT | R/O | StringRange R/O |
| info.frame | TEXT | R/O | StringRange R/O |
| info.angle | FLOAT | R/O | DoubleRange R/O (0.0 .. 0.0) |
| info.initialized | BOOLEAN | R/O | BooleanRange R/O (true false) |
| config.polarizationId | TEXT | SAVE SETUP | StringRange |
| config.separationMode | CHOICE | SAVE SETUP | EnumRange (HORIZONTAL-BELOW HORIZONTAL-ABOVE) |
| config.separationValue | FLOAT | SAVE SETUP | DoubleRange (0.0 .. 0.0) |
| rxPol | CHOICE | EnumRange (UNKNOWN) | |
| txPol | CHOICE | R/O | EnumRange R/O (UNKNOWN X Y) |