RESEARCH CONCEPTS RC1500B Manual page 24

18
RC1500B Single Axis Tracking Antenna Controller
Polarotor is at a limit. To check for this, go to the MANUAL mode. If the controller thinks
that the Polarotor is at a limit "CW" or "CCW" will be displayed in the polarization position
field. To correct this condition depress the Pol CW or Pol CCW key to 'position' the polarotor
away from the limit.
3.3.2 Configuring the RC1500 for use with a Polarotor
The Polarotor is a 3 wire servo that controls the orientation of probe in the throat of the feed
assembly. To configure the RC1500 to control a Polarotor device, set the 24 vdc Rot Feed
CONFIG mode item to 0-No.
The Polarotor was originally developed by Chaparrel Communications. Most Polarotor
modules use a standard wire coloring convention (outlined in the following table). A shielded
cable with a bare drain wire should be used to interface the Polarotor to the controller. The
shield is used in a manner identical to that described for the antenna position sense interface in
section 3.2.2.
Figures 3.2 and 3.3 show the connection of the Polarotor to the controller. The following table
details the interface of a Polarotor to the RC1500 ...
RC2000 Connection
J1-11 labeled 5.7 VDC
J1-10 labeled PULSE
J1-9 labeled RTN
J1-9 labeled RTN
The Pulse output waveform is has an on time that varies from 0.8 to 2.2 milliseconds. Varying
the output waveform on time over this range results in approximately 200 degrees of
mechanical movement of the polarotor output shaft. The waveform off time is between 15 and
20 msec. Note that the waveform is only present when a polarization skew operating is in
progress or immediately after an operation terminates.
3.3.3 Rotating Feed with Potentiometer Position Feedback
With the RC2KPOL option, the RC1500 can control a 24 volt DC rotating feed with
potentiometer feedback (400 ma max motor drive current). The RC2KPOL is frequently used
to control a Seavey Engineering model 124 ESA rotating feed. The RC2KPOL is a daughter
board that is mounted on standoffs above the controller's digital board. If the RC2KPOL is
installed a 5 position, removeable, clamp style connector will protrude from a rectangular
opening in the controller's back panel above the AGC adjustment pots. The connector is
labeled J4.
If the RC2KPOL daughterboard is not present the rectangular opening will be covered with
silver tape. Note that the RC2KPOL daughterboard can optionally be configured at the factory
for other output voltages. Contact the factory for more information. If the current rating of the
RC2KPOL motor drive outputs is not sufficient for a given application, please contact the
factory for other options.
Research Concepts, Inc.; 5420 Martindale; Shawnee, KS 66218
Signal Description
DC Power for the Polarotor
module.
Pulse Output to the Polarotor
module.
DC Power return
Cable Drain Wire
Chapter 3 Installation/Setup
Polarotor Wire Color (typical)
Red
White
Black
Must be open and isolated
from ground at the polarotor.
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