This chapter gives a short overview about some configuration parameters you want to set after you have installed the sat-nms LBRX beacon receiver. A complete reference of all available setup parameters is given in chapter 3.4 Installation Parameters .
LO Modes
As of software version 2.3 the beacon receiver offers two different modes to handle local oscillators. The LEGACY mode treats LOs in the well known way as most receivers do. There are two frequency bands with two LO frequencies, separated by a band edge (or 4 bands with three edge frequencies for models equipped with an 8-port input switch). The receiver selects the LO frequency by comparing the entered frequency to the band edge(s). If configured to AUTO, the LNB voltage and the 22kHz tone are set according to the selected band. With an integrated multiswitch, the input terminals are assigned to frequency bands and polarizations in a predefined way which cannot be changed by the operator.
The 8-LO-MODE works in a more flexible way. There are eight frequency bands defined, each of the mis addressed by a RF frequency range (min/max) and a receive polarization. Each time, the receive frequency or the receive polarization is set, the receiver scans the table of frequency bands and selects the first band (starting from top) which matches the frequency and polarization setting.
Then the receiver applies the settings defined for the detected band. This includes the LO frequency and the LNB supply / input switch settings. Receiver models providing an internal 8-way multiswitch can be configured to control this switch to any of the 8 positions. Alternatively the LNB voltage and the 22kHz tone may be switched to values stored with the individual band.
LNB LO Frequencies (LEGACY mode)
The receiver lets you enter the receiver frequency in terms of the RF frequency at the antenna. You have to configure the LNB conversion frequency at the receiver's setup page. The receiver is prepared to manage separate LO frequencies for a lower and a upper band LNB. The setup parameter you have to configure are:
Beacon receivers equipped with an optional 8-way input switch provide 4 LO frequencies and three band edge value to separate the frequency bands:
LO frequency limits (LEGACY mode)
These parameters let you specify the frequency limits for each local oscillator frequency. When entering a receive frequency, the sat-nms LBRX first selects the appropriate LO by comparing the frequency value to the band edges defined above. Then it checks the frequency to be within the the limits defined for this LO and finally sets the L-band frequency calculated from the receive frequency and the selected LO.
When you change a LO frequency, the limits for this LO automatically are set to the maximum range the sat-nms LBRX can receive with this LO. Then you may reduce the frequency range by modifying the limit parameters but you cannot enlarge the range outside the limits given by the sat-nms LBRX' L-band frequency range.
LNB Supply Voltage (LEGACY mode)
The receiver is able to supply a LNB through the L-band cable. Set the 'LNB voltage' parameter to the appropriate value. The special value 'AUTO' enables the LNB supply voltage and switches between 14V and 18V following the receive polarization you set. If you use a version with integrated Input-Switch, the LNB power supply is switched on and off by the corresponding DIP-switch on the rear panel. The sat-nms beacon receivers with integrated block down converters (BDC) do not provide this functionality when internal BDCs are active.
LNB Frequency Band Selection (LEGACY mode)
For antennas switching between frequency bands with a 22kHz tone controlled switch the receiver is able to generate the 22kHz tone either permanently or automatically depending on the receive frequency. Set the '22kHz tone' parameter to one of the settings OFF, ON or AUTO.
Frequency Band Parameters (8-LO-MODE)
When switched to 8-LO-MODE, the receiver provides a list of eight frequency bands. For each band the following parameters are configurable
LNB voltage and 22kHz switch mut be set to AUTO in order to make them available for the automatic band selection.
Relay 2 Function
One of the relay outputs available at the J1 connector may be programmed to act either as a level alarm (the circuit opens if the receive level falls below a adjustable level) or as a frequency tracking alarm. The latter indicates that the frequency tracking function does not recognize a trackable signal. This is much like the 'lock alarm' of a coherent receiver.