9.697 V4L-DVBS2-Demod

This page describes the device driver and the device window for V4L (video for linux) based DVB-S2 receiver cards. The driver has been tested with a TurboSight TBS6981 dual receiver card, it may work also with other cards based on V4L but this cannot be guaranteed.

The sat-nms software operates this card as a receive quality measurement device only. No demuxer, or video/audio decoder is included with the software used for this card.

ATTENTION

TurboSight TBS6981 cards require a 64bit Linux system and a special kernel module to be installed. The cards will not work on a "standard" VLC/M&C system.

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 .

Configuration parameters

At the maintenance page of the device window there are a couple of configuration parameters which must be set to make the software talk to this device.

parameter description
address Leave this field empty, the protocol address is not used by the device driver. Each individual demodulator unit is addressed by the interface address specified in the device configuration screen (See 'installation' at the end of this page).
22kHz Makes the device apply a 22 kHz tone to the LNB power when set to ON.
22kHzAuto If set to ON, the driver switches the 22 kHz tone depending on the receive frequency. Frequencies above the 'bandEdge' value cause the 22kHz tone to be switched on, lower frequencies switch the tone off. The 22kHzAuto mode overwrites the the '22kHz' setting described above.
lnbPower Selects if the device shall apply LNB power to the input.
lnbVoltage Selects the LNB power supply voltage (13V/18V). This switches the polarization (13V=Vertical) with some LNBs.
lnbPolSwitch If you set this parameter to ON, the 'lnbVoltage' parameter above becomes read-only and the LNB voltage is controlled though the 'polarization' parameter of the device driver (only makes sense with lnbPower=ON).
loFreqHigh The LO frequency for the high frequency band. The software sets the appropriate LO frequency every time before it changes the receive frequency.
loFreqLow The LO frequency for the low frequency band. The software sets the appropriate LO frequency every time before it changes the receive frequency.
bandEdge The frequency where the software switches the LO frequencies.
deviceComment An optional text entered here appears as an addition to the tooltip which is shown while the mouse is placed over a device icon in the GUI. The "\n" character sequence is translated into a newline character, splitting the text into multiple lines.

Installation

The TBS6981 is a dual DVB-S2 receiver, hence there are two instances of the driver to be configured for each card.

When configuring a V4L-DVBS2-Demod device in the device configuration screen, you have to specify the card's adapter/frontend number in the linux /dev/dvb directory tree instead of the device's interface name. The address consists of 2 digits "x.y" , where:

Example: "1.0" specifies the first frontend on the second card in the computer.

A TBS6981 card appears as two adapters with one frontend each, thus giving the addresses "0.0" , "1.0" for the first card and "2.0" , "3.0" for the second card in the system.

Variables defined by this device driver

name type flags range
info.driver TEXT R/O StringRange R/O
lowLevel.cmd TEXT StringRange
lowLevel.reply TEXT R/O StringRange R/O
faults.99 ALARM R/O AlarmFlagRange R/O (Communication)
faults.commstat TEXT R/O StringRange R/O
info.type TEXT R/O StringRange R/O
info.port TEXT R/O StringRange R/O
info.frame TEXT R/O StringRange R/O
info.serialno TEXT R/O StringRange R/O
info.cardid TEXT R/O StringRange R/O
info.version TEXT R/O StringRange R/O
config.22kHz CHOICE SAVE SETUP EnumRange (OFF ON)
config.22kHzAuto CHOICE SAVE SETUP EnumRange (OFF ON)
config.lnbPower CHOICE SAVE SETUP EnumRange (OFF ON)
config.lnbVoltage CHOICE SAVE SETUP EnumRange (13V 18V)
config.lnbPolSwitch CHOICE SAVE SETUP EnumRange (OFF ON)
config.loFreqHigh INTEGER SAVE SETUP IntegerRange (0 .. 0)
config.loFreqLow INTEGER SAVE SETUP IntegerRange (0 .. 0)
config.bandEdge INTEGER SAVE SETUP IntegerRange (0 .. 0)
config.deviceComment TEXT SAVE SETUP StringRange
dvbmode CHOICE SAVE EnumRange (DVBS DVBS2)
frequency FLOAT SAVE DoubleRange (0.000 .. 0.000)
symbolRate FLOAT SAVE DoubleRange (0.000 .. 0.000)
modulation CHOICE SAVE EnumRange (QPSK 8PSK 16APSK QAM16 QAM32 QAM64 QAM128 QAM256 QAMAUTO VSB8 VSB16)
fec CHOICE SAVE EnumRange (AUTO 1/2 2/3 3/4 3/5 4/5 5/6 6/7 7/8 8/9 9/10 NONE)
polarization CHOICE SAVE EnumRange (H V)
rolloff CHOICE SAVE EnumRange (AUTO 20% 25% 35%)
flags.signal BOOLEAN R/O BooleanRange R/O (true false)
flags.carrier BOOLEAN R/O BooleanRange R/O (true false)
flags.feclock BOOLEAN R/O BooleanRange R/O (true false)
flags.sync BOOLEAN R/O BooleanRange R/O (true false)
flags.rxlock BOOLEAN R/O BooleanRange R/O (true false)
state.ebno FLOAT R/O DoubleRange R/O (0.0 .. 0.0)
state.level FLOAT R/O DoubleRange R/O (0 .. 0)
state.ber FLOAT R/O DoubleRange R/O (0.0E+00 .. 0.0E+00)
internal.f FLOAT R/O DoubleRange R/O (0.000 .. 0.000)
internal.h INTEGER R/O IntegerRange R/O (0 .. 0)
internal.t TEXT R/O StringRange R/O
internal.v TEXT R/O StringRange R/O
internal.stat INTEGER R/O IntegerRange R/O (0 .. 0)
faults.01 ALARM R/O AlarmFlagRange R/O (RX Lock)