Research Concepts RC2000C - Manual (Page 24)

16 RC2000C Az/El Tracking Antenna Controller Chapter 3 Installation/Setup
Research Concepts, Inc. • 5420 Martindale Road • Shawnee, Kansas • 66218-9680 • USA www.researchconcepts.com
movement. The user must be careful to not move the motor past a limit. Damage to the rotating
feed, polarization motor, or potentiometer may occur if the limits are exceeded. If the user attempts
to jog the polarization motor and no movement is detected on the position sense lines, or movement
is detected in the wrong direction, the ANTENNA POL alarm will activate. If a polarization alarm is
active, an error message will flash on the bottom row of the display, and the polarization drive will
be disabled. The alarm can be de-activated via RESET mode.
4. Once the polarity of the motor drive and sense lines have been verified, the pol limits may be set.
To set the limits, the pol motor is jogged to the positions where it is desired to set a limit. This is
done from MANUAL mode (with the Rotating Feed CW Limit and CCW Limit CONFIG mode items
set as described above). It is recommended that an assistant be stationed at the antenna to ensure
that the polarization motor's (or sensor's) mechanical limits are not exceeded. Record the count
shown on the display at each of these positions for CW and CCW limit. Return to CONFIG mode,
and enter these new limits for Rotating Feed CW Limit (the lower value) and Rotating Feed CCW
limit (the greater value).
3.4 Setting Azimuth and Elevation Limits
The next step in the installation procedure is to ensure that the polarity of the motor drive wiring is
correct, the position sensors and Polarotor tm function properly, and then to set the azimuth and
elevation limits. If there is an optional 24V-polarization drive installed, the Polarotor tm function does not
need to be checked. If the Polarotor tm does not function properly (or if there is no polarization control of
any type in the system), make sure that the Rotating Feed Present CONFIG mode item is set to 0.
Note that not all versions of the software support polarization control. If the controller being installed
does not support polarization control ignore the references to polarization control.
All of the operations outlined in this section can be carried out with the controller in LIMITS mode. In
LIMITS mode the user has unrestricted movement of the antenna, there are no software azimuth
or elevation limits, and antenna jammed sensing does not take place. When moving the antenna
in LIMITS mode an assistant should be stationed at the antenna to insure that the antenna does
not move past a physical limit. Note also that the CW and CCW polarization adjustment keys are
active.
3.4.1 Motor Drive Polarity
The polarity of the azimuth motor drive is checked by depressing the AZ CCW key and verifying that the
antenna moves in the proper direction. The sense of azimuth movement is as seen by an observer
located above the antenna. In the northern hemisphere depressing the AZ CCW key should result in
east movement. If the antenna does not move in the proper direction, connector J2 pins 4 and 6 need
to be reversed. The polarity of the elevation motor drive is checked in a similar fashion.
The azimuth and elevation position sensor operation can be checked by jogging the antenna about the
appropriate axis and verifying that the position count changes for that axis. Note that the position count
will always decrease for AZ CCW and EL DOWN movement, and will always increase for AZ CW and
EL UP movement. Also the count will not decrement lower than 1 or increment higher than 65535.
Polarotor operation is checked by using the POL CW and POL CCW keys to skew the polarization (on
those controllers that support polarization movement).
3.4.2 Setting Limits
The azim counter-clockwise and/or elevation down limits are set first. The bottom row of the display
prompts the user to set the limits for each axis. To set a limit, position the antenna using the Az/El jog
keys at the desired limit, and hit either the 7 key to set an azimuth limit or the 9 key to set an elevation
limit. When the azimuth counter-clockwise limit or elevation down limit is set, the position count for the
axis is reset to 30. The limits should be specified so that there is adequate clearance between the
antenna and any obstacles when the antenna is positioned at any azimuth/elevation combination within
the limits.