Southern Avionics Company SD100 Manual Do Utilizador

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SD SERIES TRANSMITTER                             
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SOUTHERN AVIONICS COMPANY
  SECTION 2
2 THEORY OF OPERATION, SD SERIES UNIT
2.1 Functional Description: SD Series Transmitter
General Theory of Operation
Briefly, the SDxx  system takes advantage of the powerful  Motorola ColdFire(r)  microprocessor.  It is located on the 
Controller / Monitor PCB and is the heart of the system, generally controling all system operation  either directly or in 
conjunction with an Analog and Digital I/O multiplexing interface. 
The following are all controlled by the embedded firmware,  Direct Digital Synthesis (DDS) of RF 
frequency and AF tone frequency , Identifier Morse code dot, dash and space intervals., Customer IDENT sequence, 
the standard alarms, any additional Fault handling based on multipoint voltage, current and temperature monitoring , 
transfer criteria (Dual Only),  power limiting and  modulation limiting.
RS 232,RS422 and RS485 protocols are supported. A US Robotics Modem is furnished for using phone lines. 
The RF section consists of the RF PA Power Supply, The RF PA Amplifier, The Filter /Bridge, and the 
Mother Board which interconnects them all. This section is interconnected with the Controller/Monitor which 
Dictates the Frequency of operation, power output, and modulation percentage.   Operational information is also 
passed. A more detailed breakdown as to functionality follows on a board by board basis. 
SLP10007 - Controller / Monitor
The CONTROLLER/ MONITOR employs the new Motorola MCF5206 COLDFIRE(r) microprocessor. It 
encompasses the following sections:
COLDFIRE Processor - 32-bit
ADC - 8-Channel 12-bit
DAC - 8-Channel 8-bit
DDS - Radio Frequency (190K to 1800KHz)
DDS - Tone Frequency (400 / 1020 Hz)
Flash Memory - 4Mb
DRAM - 16Mb
Programmable Logic
Digital I/O (Read/Write)
UART
Watch Timer and NV-RAM
COLDFIRE Processor section:
The LOGIC program creates 16MHz from 32MHz for the clock frequency of the microprocessor. The processor 
controls several peripheral functions such as memory, task timers, I/O bus lines, and RS-232 ports. For the dual 
system, the primary Controller / Monitor and secondary Controller / Monitor may talk to each other through 
Controller / Monitor Motherboard (SLP10012) by using 2 COM-PORT lines (ex: RXD & TXD). Each Controller / 
Monitor has one interrupt line for paying attention what other Controller / Monitor has something is important, then 
Controller / Monitor sets "RS-232" MUX to be enabled.
Analog-to-Digital converter (ADC) section:
The Controller / Monitor Controller PCB has two (AD7891) 12-bit ADC chips, so there are 16 analog inputs. The 
channel selection of input range is 0 to +5 V.