RC4500 Antenna Controller Chapter 5 MODES – In Depth Descriptions
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*** NOTE: The Track Factors screen will only be available on RC4500 controllers that were purchased
with the inclined orbit tracking option. ***
5.2.1.3.10 Track Factors
SEARCH: 3 CONFIG-TRACK
MAX ERROR: 3 TIME: 2
HOLDOFF:120 LOG:0 AZDP:1.0
<0-MANUAL,1-NARROW,3-NOMINAL,10-WIDE>
SEARCH: <0-MANUAL,1-NARROW,3-NOMINAL,10-WIDE>
The track_search_scale_item specifies whether or not the Intelli-Search algorithm is enabled or disabled,
and if enabled it controls the width of the sweeps which occur during execution of the Intelli-Search
algorithm. When the STEP TRACK submode is active and the signal strength input indicates that the
satellite transponder has gone down, the controller will switch to the SEARCH sub-mode.
If the Search item is disabled (by setting it to 0-MANUAL), the user is simply prompted to manually
position the antenna on the satellite and hit the ENTER key to continue. The Intelli-Search should be
disabled for transmit applications. It may also be advantageous to disable Intelli-Search for antennas
which move very slowly.
If the Search CONFIG mode item is enabled, the controller will execute the Intelli-Search algorithm.
During an Intelli-Search, the controller will perform a serpentine-shaped search over a region where the
controller has calculated that the satellite's apparent motion will take it. If the satellite is not found during
the Intelli-Search, the search is periodically repeated until either signal strength information is available, or
track table information becomes available.
If the angular extent of the sweeps is too large, the controller could mistakenly align the antenna with an
adjacent satellite. A search with narrow sweeps takes much less time to complete, but may not sweep
over a region which is wide enough to find the satellite.
The Search width is not an absolute value - increasing its value results in wider sweeps, and decreasing
its value narrows the sweeps. The actual pointing angle over which search sweeps occur is a function of
the antenna beamwidth and the Search Width parameter. For a given Search Width value, the search
sweeps of an antenna with a narrower beamwidth will be greater than for an antenna with a larger
beamwidth.
The default Search value of 3 is appropriate for satellites with 2 degree spacing. For faster searches, the
value can be lowered to 1 or 2.
MAX ERROR: ENTER MAX ERROR IN TENTHS OF A dB<1-30>
The max_track_error_tenths_db item specifies the maximum antenna tracking error in tenths of a DB.
This parameter has more influence over the operation of the tracking system than any other. The
significance of this variable is described in detail in sections 4.2.1 and 4.2.2 of this manual, which cover
the operation of the controller in the STEP TRACK and PROGRAM TRACK sub-modes.
In the STEP TRACK sub-mode, the value of this parameter determines how often peaking operations
occur. The controller will peak the antenna often enough so that between peakups the signal strength
variation due to antenna pointing error will not exceed Max Track Error tenths of a dB.
In the PROGRAM TRACK sub-mode, the controller tracks that satellite based on the current sidereal time,
and data in the track table. The controller will reposition the antenna often enough so that the error
between the antenna's azimuth and elevation position and the azimuth and elevation positions derived
from interpolation of track table data is less than Max Track Error tenths of a dB.
The Max Track Error parameter specifies the azimuth and elevation step sizes during peaking operations
which occur during the STEP TRACK and PROGRAM TRACK sub-modes. Some users erroneously
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