RESEARCH CONCEPTS RC4500 - Scale Factors; Azimuth Scale Factor; Elevation Scale Factor

RC4500 Antenna Controller Chapter 4 Software Configuration / Installation
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4.2.4 Scale Factors
Note: in most cases the default scale factors for a mount will be correct and should NOT be
changed
For resolver-based position sensing, the RC4500 utilizes a 16 bit resolver to digital converter which
generates a count value from 0 to 65,535. Typically the resolver sensor rotates with the antenna. The
resulting “pulse scale factor” therefore is:
. Perform scale factor calibration only if the Appendix B suggests that the scale factor for
your particular mount should be characterized.
65536 resolver counts / (360 degrees * 1 radian/57.29 degrees) = 10430.2 “pulses” / radian
The default scale factor for a resolver system is therefore rounded up to 10431
4.2.4.1 Elevation Scale Factor
The elevation position sensor is the resolver and the scale factor is a constant that should not be changed.
The elevation scale factor can be found in the CONFIG – ELEVATION CALIBRATION screen.
CONFIG-ELEV
DOWN: 0.000 UP: 90.000
PSF:10431 ROFF:-180.000 DIR:0
DOWN LIMIT <-20.000-120.000 DEGREES>
PSF: PULSE SCALE FACTOR <1 – 32767 CNTS/RAD>
This value specifies the approximate number of pulses measured per radian of elevation travel. This
value allows the ACU to correctly display the resolver position in angular format. This value is also used
by inclined orbit tracking algorithms for determining movement amount (in pulses.)
NOTE: The default value for this item will typically be correct.
4.2.4.2 Azimuth Scale Factor
The azimuth position sensor is the resolver and the scale factor is a constant that should not be changed.
The azimuth scale factor can be found in the CONFIG – AZIMUTH CALIBRATION screen.
CONFIG-AZIM
CCW:-180.000 CW: 180.000
PSF:10431 ROFF:-180.000 DIR:0
CCW LIMIT <+/-300.000 DEGREES>
PSF: PULSE SCALE FACTOR <1 – 32767 CNTS/RAD>
This value specifies the approximate number of pulses measured per radian of azimuth travel. This value
allows the ACU to correctly display the resolver position in angular format. This value is also used by
inclined orbit tracking algorithms for determining movement amount (in pulses.)
NOTE: The default value for this item will typically be correct.