Technical Manual

A-14 ATLAS 4500 Multimode Station Technical Manual December 2016
Controller Board Appendix A - UHF Circuit Descriptions
A.4.2.5 Fan Control
The PA fan interface has 4 pins. 12 V Power is switched with a pulse width FET.
Fan power noise spikes are attenuated by RFI network using L1 etc to eliminate
noise on 12 V power.
A speed control is provided for the fan. A pulse RPM sensor allows RPM to be
measured.
A.4.2.6 External Port and Serial Links
The Controller PCB has an external 10-pin port for diagnostic use with jumper
links JMP2 and JMP3 to select Debug access to MCU position A. Debug access to
Exciter position C.
The Controller can be talked to in position A of links JMP2 and JMP3 to its serial
port 2 and debug or loader program used. (To use the loader JMP1 must be taken
off)
The DSP I/F normally accesses controller serial port 1 but when DSP is not
connected this can also be selected using links JMP4 and JMP5 Position B.
(normally always A).
A.4.2.7 Auxiliary
The Controller PCB has 2 x 3.3 V linear regulators and a 5-V linear regulator.
It contains an interface for the 10 front panel LED indicators. (some future use)
These are for Power, Analog, RXA, RXB (diversity), Link (Ethernet on), P25
phase 1 (C4 FM), P25 phase 2, TX A (time slot A), TX B (time slot B).
The CPU A/D inputs monitor voltages for Supply in (48 V), RX VCO 2, RX VCO
1, TX VCO, Forward and Reflected voltages.
The Controller sends serial data on 3 lines to the PA 7 bit attenuator ATN1, ATN2,
ATN3 for SI, CLK, LE pins on the attenuator IC.
The Controller has an input port for the temperature sensor sending a pulse width
modulated signal.
A.4.2.8 Firmware
The Controller flash contains the following: