Research Concepts RC2500 - Manual (Page 26)

RC2500 Antenna Controller Chapter 3 Installation/Setup 19
Research Concepts, Inc. • 5420 Martindale Road • Shawnee, Kansas • 66218-9680 • USA www.researchconcepts.com
3.3.3 AGC interface Connection
J1 is a DB-15 receptacle used primarily for AGC signal input while the RC2500B is tracking inclined orbit
satellites. The RC2500A model does not support inclined orbit tracking modes. In addition to the AGC
input function, J1 supports 4 bits of digital I/O and various bus voltages that allow for future expansion.
The AGC voltage or received signal strength voltage from the system receiver must be between –15VDC
and +15VDC. The signal may be either positive-going or negative-going for an increasing signal strength
(selectable in the configuration menu). When the magnitude of the difference between the “on satellite”
voltage and “off satellite” voltage is less than 1.3 volts AGC channel 1 should be used. For voltage
differences greater than 1.3 volts use AGC channel 2. Four potentiometer adjustments at the back panel
set the gain and offset for the two channels.
A shielded pair such as Alpha 1292C should be used to minimize external noise pickup on the AGC line.
The shield should be connected at the RC2500 system ground and open circuited at the receiver or
modem. For further discussion of the AGC inputs, AGC input tuning, and inclined-orbit tracking see
Chapter 4.
The individual pin definitions of J1 are shown in the table below.
Pin # Description
1 PC4 digital I/O, 2.5 mA drive capability, currently unused.
2 PC5 digital I/O, 2.5 mA drive capability, currently unused.
3 PC6 digital I/O, 2.5 mA drive capability, currently unused.
4 PC7 digital I/O, 2.5 mA drive capability, currently unused.
5 Digital ground.
6 +5 Volts DC digital power, 200mA max.
7 AGC signal return path (ground)
8 AGC 1 (high gain path) signal input.
9 Unregulated +24 VDC bus voltage, 1 Amp max.
10 Ground for system bus voltages.
11 -12 Volts DC regulated supply, 40mA max.
12 +12 Volts DC regulated supply, 40mA max.
13 AGC 2 offset voltage test point (used during AGC 2 calibration)
14 AGC 1 offset voltage test point (used during AGC 1 calibration)
15 AGC 2 (low gain path) signal input.
3.3.4 PC Remote Control Interface Connection
J5 is a DB-9 receptacle used for the RS-422 remote control interface of the RC2500. Most PC serial
ports conform to the RS-232 standard that allows communications between just two devices. The RS-
422 standard of the RC2500 allows several devices to be connected on the serial line and be controlled
in an addressable manner. A converter (such as RCI p/n RC1KADP) must be used when controlling the
RC2500 with an RS-232 port. In order for serial communications to occur the CONFIG mode item
REMOTE MODE ENABLE must be set to 1 and the COMM PORT ADDRESS and COMM BAUD RATE
must be set. For a complete discussion of the PC remote control features of the RC2500 see
Appendices C, D, and E.
Mis-connections of J5 with J2, J3, or J4 will not cause system damage. The individual pins defined from
the perspective of the RC2500 are shown in the following table.