--- This page shows the operational parameters.
--- The device info page.
--- The maintenance page. The configuration parameters described below are set at this page.The Uplink-Power-Control-2 logical device adjusts the level of a transmit signal in order to compensate the atmospheric attenuation in the signal uplink. To achieve this, the Uplink-Power-Control logical device reads the level of the satellite's beacon from a beacon receiver or from another signal source. Unlike the Uplink-Power-Control device, which is optimized for a permanent long term transmission, the Uplink-Power-Control-2 device is intended to be used with occasional use transmissions.
Functional description
The device controls and adjusts a transmit level by adding the deviation between a measured beacon level or signal value read from another uplink power control and its nominal value to a given nominal transmit power. A new power value is set every time either the measured level or one of the operational parameters change.
Operational parameters
There are a number of operational parameters which can be used to tune the behaviour of the Uplink-Power-Control-2 device:
| parameter | description |
|---|---|
| nominalOutput | The nominal transmit power value (usually in units of EIRP). This value must be set to make the uplink power control work. |
| nominalInput | The nominal value of the receive level or what reference value is used for the uplink power control. |
| upcEnable | Switches the uplink power control on or off. Switching OFF sets the output power to its nominal value. |
| maxPwrIncrease | Limits the increase of the output power with respect to the nominal value (dB). |
| maxPwrDecrease | Limits the decrease of the output power with respect to the nominal value (dB). If the nominal values refer to clear sky conditions, this value wil be 0 in most cases (no decrease of the output power). |
| ratio | The deviation of the measured input value is multiplied with this ratio setting before the result is added to the nominal output power. Hence, the ratio value fan be used to control the direction and the intensity of the uplink power control (see section 'Control ratio' below). |
Power on behaviour
The Uplink-Power-Control-2 device does not permanently store the nominal transmit power level. When the sat-nms server starts, the nominal transmit power is unknown and the uplink power control is inhibited until this value is set. This can be done by the operator by setting this value explicitly or by another logical device which commands a transmit power for a new job.
Control ratio
The 'ratio' parameter is used to adapt the uplink power control behaviour to the kind of reference value used as input.
If the input is a beacon level, the ratio value must be negative (e.g. -1.0). If the beacon level falls below the nominal value, the output power shall increase.
The uplink power control also my be operated as a slave to another power control. If the deviation of the output power of this other uplink power control device is used, the ration parameter must be positive (+1.0). If the other uplink power control raises the output power, we do as well.
When used with a beacon level, the device has to estimate the atmospheric attenuation in the uplink from a lowering of the beacon (downlink) level. As transmission usually is done at higher frequencies than the downlink, the uplink atmospheric attenuation will be higher than the measured beacon level degradation. This might be a reason to set the ratio value to a value like -1.2 in order to cover this effect.
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 .
--- This page shows the operational parameters. --- 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 interconnect the Level-Set device to the devices it monitors and controls.
| parameter | description |
|---|---|
| pwrSetId | The parameter ID which controls the transmit level. In most cases this will be the 'eirp' parameter of the Level-Set or Level-Control logical device which controls the transmit power. If no Level-Set or Level-Control device is used, a modulator level or upconverter gain parameter may be used as well. |
| pwrMeasId | The ID of the parameter indicating the satellite beacon level (or another reference value to be used). |
| enableId | The ID of a parameter which enables the UPC. If this parameter is configured, the UPC works only if upcEnable is set ON, and the parameter addressed by this enableId is one of 'true', 'YES' or 'ON'. |
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 |
| config.pwrSetId | TEXT | SAVE SETUP | StringRange |
| config.pwrMeasId | TEXT | SAVE SETUP | StringRange |
| config.enableId | TEXT | SAVE SETUP | StringRange |
| nominalOutput | FLOAT | DoubleRange (0.00 .. 0.00) | |
| nominalInput | FLOAT | SAVE | DoubleRange (0.00 .. 0.00) |
| upcEnable | CHOICE | SAVE | EnumRange (OFF ON) |
| maxPwrIncrease | FLOAT | SAVE | DoubleRange (0.00 .. 60.00) |
| maxPwrDecrease | FLOAT | SAVE | DoubleRange (0.00 .. 60.00) |
| ratio | FLOAT | SAVE | DoubleRange (-5.00 .. 5.00) |
| inputDelta | FLOAT | R/O | DoubleRange R/O (0.00 .. 0.00) |
| outputDelta | FLOAT | R/O | DoubleRange R/O (0.00 .. 0.00) |
| inputPower | FLOAT | R/O | DoubleRange R/O (0.00 .. 0.00) |
| outputPower | FLOAT | R/O | DoubleRange R/O (0.00 .. 0.00) |
| enabled | BOOLEAN | R/O | BooleanRange R/O (true false) |
| faults.01 | ALARM | R/O | AlarmFlagRange R/O (Power decrease limit) |
| faults.02 | ALARM | R/O | AlarmFlagRange R/O (Power increase limit) |