Research Concepts RC2500 - Manual (Page 132)

RC2500 Antenna Controller Appendix L Replacing the Electrospace 93C-23 125
Research Concepts, Inc. • 5420 Martindale Road • Shawnee, Kansas 66218-9680 • USA www.researchconcepts.com
Appendix L – Replacing the Electrospace 93C-23 Controller
It is possible to use the RC2500 to replace the Electrospace Corporation 93C-23 Antenna Controller and
enjoy the added capabilities of inclined-orbit tracking and PC remote control. In order to be compatible
with the Antenna and the 83MC4 outdoor box, resolvers are placed on the azimuth and elevation pivot
points. If the polarization axis is motorized, a resolver or potentiometer (see appendix H) must be
mounted at the polarization pivot point. Information on the connection and use of resolvers is found in
section 3.3.1. The firmware version for this unit is: version 1.12eea--, the date: 2.9.00, and the
checksum: 'AE'. The RC2500 uses the 2_5KI_O1 as the interface PCB.
Limit and Status Inputs
The 83MC4 has six, 24VDC non-isolated limit switch outputs that are directly compatible with the limit
inputs of the RC2500 using the Standard I/O board with isolated inputs. The “Limit Status” terminals of
the 83MC4 are connected to the limit input and the limit “Drive Gnd” terminals of the 83MC4 are
connected to the limit return lines. The “safe” operating region is defined as the conducting state of the
drivers. That is, an open-circuit occurring on the limit status line of the RC2500 input terminal indicates a
limit has been reached. All six positional limits operate in this manner.
Three other inputs represent System Interlock, AZ Interlock and EL Interlock. The AZ and EL interlock
lines, which, under normal conditions, provide 24VDC, go to an open circuit when the AZ or EL motor
circuit breakers trip. These two lines are connected to the AZ Drive fault and EL Drive Fault inputs.
When the motor circuit breakers trip, an appropriate drive fault message will be displayed on the RC2500
front panel. To clear these faults, the circuit breakers in the 83MC4 must be switched to the “on” position
and then the drive error may be cleared at the RC2500 as described is section 5.6.
The system Interlock provides 24VDC under normal conditions and shows an open circuit when the
system interlock is opened or the emergency stop switch is actuated. The system interlock status is
connected to the RC2500 Emergency stop input and the Maintenance Status input. Loss of 24V at this
point will also cause all position limits to be asserted, AZ and EL Faults, and Emergency Stop will show
on the front Panel. After the System Interlock and/or Emergency Stop switches are returned to their
normal positions the remaining drive faults may be cleared as described in Section 5.6.
A tenth input, ACU/LOCAL Status, lets the RC2500 know whether the antenna is being jogged under
local control at the base-mounted A.I.U. This line is connected to the Maintenance status return line of
the RC2500. When Local Mode (RC2500 to be disabled) is activated, by flipping the ACU/LOCAL switch
to “LOCAL”, this line is pulled to ground potential and the maintenance optical isolator will go into a
conducting state. The RC2500 will indicate “MAINTENANCE” flashing on the lower line of the display
until the switch is flipped to “ACU”.
The Output of the RC2500 with its 24V x 700mA open-collector drivers are directly compatible with the
drive inputs to the 83MC4 outdoor box. There are 10 drive inputs for the maximum configuration
Electrospace AIU. These are: AZ Enable, AZ CW/CCW, AZ Slew, AZ Brake, EL Enable, EL UP/DOWN,
EL Slew, EL Brake, POL Enable, and POL CW/CCW.
The Interface between the RC2500 ACU and 83MC4 AIU is summarized in the following tables showing
all connections at J6 and J7. There are 13 connections labeled Drive Ground. All of these connections
must be connected to the Drive Ground pins of the 83MC4 AIU.
Antenna I/O Connector
J7, located to the right of J4, is a DB-25 plug identified as the Antenna I/O connector. This connector
acts as the antenna motion control port of the RC2500. The port consists of 9 solid-state low-side relay
drivers rated at 700mA sink each. Max voltage is +27VDC on these drivers. Current is returned to the
A.I.U. via the Drive Common line (pins 2,5, and 8). In addition to the drivers, this port supports three 24
VDC, low current, status inputs with isolated returns. The individual pin definitions as well as their mating
connection at the 83MC4 are shown in the table below.
RC2500 Pin #
& (resource) Description 83MC4 Pin #
1 (PA1) Azimuth Direction, pull-down drive, 700mA max sink. AZ CW/CCW TB3-4