Research Concepts RC2500 - Manual (Page 145)

138 RC2500 Antenna Controller Appendix O Replacing the Andrew APC100/ APC 300
Research Concepts, Inc. • 5420 Martindale Road • Shawnee, Kansas • 66218-9680 • USA www.researchconcepts.com
Appendix O – Replacing the Andrew APC 100/ APC 300
It is possible to use the RC2500 Antenna Control Unit (ACU) to replace the Andrew APC 100 / APC 300
Antenna Controller and enjoy the industry-standard RCI operator interface. In order to be compatible with
the Antenna and the Andrew Local Motor Controller (LMKDS), resolvers are placed on the azimuth,
elevation and polarization pivot points. Information on the connection and use of resolvers is found in
section 3.3.1. For retrofit installations, the existing resolvers may work if they operate with a 4.4Vrms,
2KHz reference and have a transformation ration of 2:1. The firmware version for this unit is: version
1.14 waa--, the date: 4.3.00, and the checksum: '34'. The RC2500 uses a modified 2_5KI_O1 as the
interface PCB.
LMKDS Input
The Output of the RC2500 with its 10, 24V x 700mA open-collector drivers is directly compatible with the
drive inputs to the LMKDS Local Motor Controller. There are 10 drive inputs for the LMKDS. These are:
AZ EAST, AZ WEST, AZ FAST, AZ SLOW, EL DOWN, EL UP, EL FAST, EL SLOW, POL CCW, and
POL CW. The entire interface is powered from the RC2500. Optoisolators provide isolation between the
grounding system of the RC2500 and the grounding system of the LMKDS.
The antenna has limit switches to guard against over-travel on all three axes. These limit switches
interface with the LMKDS. In the APC100/300 system, this limit information is not transmitted to the ACU.
The RC2500 ACU operates with “soft” limits. That is, a given resolver position entered from the front
panel, serves as a limit. The soft limits of course should be “inside” the antenna limit switches.
The standard I/O drive board of the RC2500 is modified to adapt to the LMKDS interface. A secondary
regulator and over-current protection stage is added to supply the required 12VDC when the RC2500 is
powering the interface. The PC0 relay is used to apply this voltage to the drive interface and remove it in
the case of errors.
The hardware interface between the RC2500 ACU and LMKDS is summarized in the following tables
showing all connections at J6 and J7. Following the interconnection tables, a description of the unique
operating firmware for this version is given.