Comtech EF Data HPCST-5000 - Manual (Page 130)

Theory of Operation High-Power C-Band Satellite Terminal
6–4 Rev. 0
6.1.2.1 Remote Interface Specification
Refer to Appendix B for information on remote control operation.
6.1.3 Terminal Default Conditions
On initial power-up, the unit will default to the following parameters:
Parameter Default
Baud Rate 9600
Parity Even
Device Address 1
U/C Gain Minimum
D/C Gain Minimum
RF Output OFF
U/C Frequency 6135.00 MHz
D/C Frequency 3925.00 MHz
6.1.4 Theory of Operation
Refer to Figure 6-3 for a functional block diagram of the M&C.
The M&C board performs the following operations:
! Receives the desired frequency from either the remote EIA-232/EIA-485 or local
keypad, and after converting it to a synthesizer setting, stores it to the applicable
synthesizer output latch.
! Reads the thermistors located in the up converter, down converter, and HPA, and
converts them to temperatures for display.
! Reads the characterization EEPROMs in the up converter, down converter, and
HPA, and calculates an Automatic Gain Control (AGC) voltage based on
frequency and temperature to linearize the respective module.
! Turns the cooling fan ON or OFF, depending on the temperature.
! Receives fault inputs from all modules, and presents them to the remote
EIA-232/EIA-485 and the optional local keypad display.
! Performs an initial current sense on the LNA, and stores the reading in the
EEPROM. Subsequent current sense readings are taken and compared to the
initial reading to determine a fault.