1.556 RX-Channel-BySatellite

The RX-Channel-BySatellite logical device controls the basic parameters of an IRD and an input switch for the IRD which selects antenna, frequency band and polarization. RX-Channel-BySatellite replaces the RX-Channel device in FILTER-BY-Satellite workflow mode on modern M&C systems which store the channel data in a central SQL database. The device complements the TX-Channel-BySatellite logical device which provides a similar function for transmit chains.

Although all individual IRD parameters are directly accessible with the device, the typical way to operate the device is to select a satellite channel from the list and to select the proper input signal for the IRD. The RX-Channel-BySatellite device assists the operator in this task with the following functions:

• The list of available input signals is dynamically generated by the device, the list entries are composed of "antenna name", "frequency band", "polarization" and satellite name. E.g. ANTENNA3-11Y-ASTRA19.2 denotes an 11GHz vertical signals, received from the ASTRA19.2 satellite through ANTENNA3. With motorized antennas, the satellite name is derived from the antenna's Antenna-Pointing device, telling the actually commanded satellite name.
• If you select a satellite channel from the database, parameters like frequency, symbol rate, DVB-S/DVB-S2 selection etc. are taken from the database and commanded to the IRD. Additionally the list of available inputs is confined to those signals which match the frequency band and polarization plane of the selected channel. You may remove this confinement at any time by selecting the "manual" satellite channel.
• The RX-Channel-BySatellite device accounts for the LO-frequency defined for a selected input and sets the proper receive frequency at the IRD (in terms of L-band frequency). If you change the input, the LO-frequency may change as well and the device commands a new frequency setting to the IRD.

With this device, the operator first selects the antenna to be used, then the satellite this antenna shall be pointed to. Selecting the satellite actually commands the antenna controller to point the antenna to this satellite. Next the device reduces the list of displayed satellite channels to those which may be received with this antenna/satellite. After selecting a channel from the list, the IRD parameters are set, the IRD input signal is selected automatically and - if necessary - the antenna is moved to point to the satellite referenced in the selected channel. Other functions of this device are:

• A locking mechanism which protects an antenna from being turned away while receiving a certain signal. An operator may "lock" an IRD which prevents the operator from changing any IRD parameters in the device screen and from turning away the antenna from this or from any other RX-Channel-BySatellite or TX-Channel-BySatellite devices.
• The locking mechanism used with this mode may be configured, that a lock only may be released from the same client PC which has set the lock.
• The device is aware of antennas with 2-port feed which may receive / transmit only at one polarization plane at a time. Locking an IRD receiving from such an antenna also locks the polarization plan selection for all devices to prevent the signal for the first IRD from being interrupted.

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 .

• --- The main control (line settings select) page for the device. The layout of this page differs for the individual operating modes
• --- The fault page
• --- The device info page.
• --- The maintenance page. The configuration parameters from this page are described below.

Operation

With this device, the 'channel' field only shows the channels of the satellite the selected antenna actually is pointed to. To move the antenna to another satellite, either the 'satellite' field in the RX-Channel-BySatellite device screen may me used or the antenna may be controlled via it's own screen. Changing the antenna pointing automatically changes the subset of satellite channels displayed in the 'channels' field. The typical sequence of operation in this mode is as follows:

1. Select the antenna to receive from (field "antenna")
2. Select the satellite to receive with this antenna if this needs to be changed (field "satellite")
3. Select the satellite channel to receive. (field "channel", shows only channels from the selected satellite)

Selecting the satellite channel will automatically select the appropriate l-band matrix input and set the IRD parameters. Only if the input selection is ambiguous, e.g. if the satellite can be received through a fixed and a motor driven antenna at the same time, the input selection must be done explicitly.

Configuration parameters

At the maintenance page of the device window there are a couple of configuration parameters which must be set to interconnect the RX-Channel-BySatellite device with the IRD and the input switch.

To make the RX-Channel-BySatellite device work, at least the frequencyId and symbolRateId fields must be set to the message IDs of the corresponding IRD parameters. If some other parameters are not supported by the IRD, leave the message ID fields empty, the same applies to the lock fault if a lock fault signalling in the RX-Channel-BySatellite device is not desired.

The configuration file format

The RX-Channel's configuration file is a plain text file which defines the matrix / switch input assignments. As this is a system wide assignment, you usually will edit one common configuration file for all RX-Channel-BySatellite devices connected to one input matrix.

In the file all empty lines and lines starting with a '#' character are ignored. All other lines are treated as table rows where the cells are separated by space characters. Each row describes one matrix input as follows:

Example:

#  Example configuration file for a RX-Chnnel-BySatellite device
#
#
#  input no.    polarization       freq. limit [MHz]
#  |            |                  |
#  |   antenna  |  LO freq. [MHz]  |
#  |   |        |  |               |

  01   ARD      X  9750.0        < 11800.0 
  02   ARD      Y  9750.0        < 11800.0
  03   ARD      X  10600.0       > 11800.0 
  04   ARD      Y  10600.0       > 11800.0 

  05   NDR      X  9750.0        < 11800.0 
  07   NDR      X  10600.0       > 11800.0 

  17   SNGR     X  9750.0        < 11800.0 
  18   SNGR     Y  9750.0        < 11800.0 
  19   SNGR     X  10600.0       > 11800.0 
  20   SNGR     Y  10600.0       > 11800.0 
   
  09   EBU      X  10000.0       < 11800.0   
  10   EBU      Y  10000.0       < 11800.0   

  11   W1       X  9750.0        < 11800.0 
  12   W1       Y  9750.0        < 11800.0 
  23   W1       X  10600.0       > 11800.0 
  24   W1       Y  10600.0       > 11800.0  

  13   ASTRA    X  9750.0        < 11800.0   
  14   ASTRA    Y  9750.0        < 11800.0   
  15   ASTRA    X  10600.0       > 11800.0   
  16   ASTRA    Y  10600.0       > 11800.0  
    
  21   EB_12V   Y  10600.0       > 11800.0   

  22   W1_V     Y  10000.0       < 11800.0   

  

The RX-Channel-BySatellite device parses this file on startup and when it receives a new name for the configuration file. So when you change the configuration file in the running M&C system, the best way is to restart the M&C server process to make all devices read the configuration file again.

Variables defined by this device driver