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RC4000 ACU Boardset
3.3.1.2.7 SS1 Signal Strength Factors
This screen defines how the signal strength inputs are used. See sections
references to the use of signal strength inputs and
LOCK:1
THRES:
SCAN RG:10
LOCK TYPE <0>NONE <1>HI <2>LO
LOCK:
LOCK TYPE <0>NONE <1>HI <2>LO
When the autopeak source is the SS1 input, this item defines whether a discrete signal lock input is
required to indicate a satellite has been found. The signal lock input may help in distinguishing the
correct satellite while doing a LOCATE.
If a signal lock input is used, it may be defined as either having a HI (>3.5 VDC) or LO (< 0.8 VDC) level
that indicates lock.
TIME:
LOCK TIME <0.0-10.0> SECONDS
This item defines how long the RC4000 will wait after each step before sampling signal strength.
Increasing this value may be required to allow equipment such as a modem to generate an AGC output.
THRES:
SCAN SLOW THRESHOLD <0-1000>
The threshold item defines what the minimum signal strength indication for the channel is required for the
tracking system to "recognize" that a satellite is present. NOTE: these items are only applicable to
TRACK mode. When the signal strength reaches this threshold level, the scan movement will transition
from fast to slow speed.
If different bands are received that exhibit different "off satellite" signal strengths, the highest "off satellite"
value should be used to avoid the possibility of recognizing noise as a satellite.
SENSE:
INPUT SENSE POLARITY <0>NEG <1>POS
The polarity flag tell the controller what the sense is on the signal strength input voltage used for tracking
and autopeak operations. A positive sense is defined as one that increases in magnitude as the RF
signal strength increases. If the signal strength voltage decreases as the RF signal increases, its polarity
is considered negative.
SCAN RG:
SCAN RANGE <1-90 DEGREES>
The scan_range item defines how many degrees to either side of the nominal azimuth target the scan
autopeak operation will search.
SRCH AZ:
SPIRAL SEARCH AZIM LIMIT <1 – 20 DEGREES>
SRCH EL:
SPIRAL SEARCH ELEV LIMIT <1 – 15 DEGREES>
The search_azim/elev_limit items define the area that the spiral search pattern is allowed to search to
recognize a satellite. If a satellite is not recognized after searching the area defined by these limits, the
spiral search will return to the normal target position. The larger the limits, the longer time a search might
take. If the limits are too small to account for azimuth target inaccuracy due to heading error or to
account for the amount of elevation movement an inclined orbit satellite may exhibit, the spiral search
may quit before moving over the satellite.
Chapter 3
section 4.1.11
TIME:1.0
10
SENSE:1
SRCH AZ: 5
109
2.1.2.2.3
for information regarding calibration.
CONFIG-SS1
SRCH EL: 5
Software
and
2.1.2.4.2
for
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