Comtech EF Data KST-2000A, Installation And Operation Manual

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Ku-Band Satellite Transceiver Revision 9
Operation MN/KST2000AB.IOM
3–24
The M&C is composed of the following sections:
• Microcontroller/UART • D to A and A to D converters
•
Fault relays
•
ROM/RAM
•
LNA power control
•
1:1 redundancy logic
•
Intermodule COMM interface
•
External I/O interface
The microcontroller is a Dallas 80C310 operating at 16 MHz. The microcontroller con-
tains 256 bytes of internal RAM. The external ROM is 29F040 (512 kbytes). The battery
backed RAM is 8 kbytes in size.
The non-volatile RAM allows the KST-2000A/B to retain configuration information
without prime power for 1 year.
The UART supports serial asynchronous communication (remote port) with a maximum
data rate of 19200 bit/s. The communications type can be EIA-232, EIA-485 (2-wire), or
EIA-422 (4-wire) half duplex.
The DAC supplies a voltage that fine tunes the reference oscillator operating frequency.
The ADC monitors the internal power supply voltages, as well as external temperature
and analog inputs from SSPAs and TWTAs.
The three fault relay outputs are failsafe. They will indicate a fault in the event of a power
outage. The three relays are uplink fault, downlink fault, and summary fault.
The M&C has built-in redundancy logic. It reads switch position and external status in-
formation from the waveguide switches and the other KST-2000A/B. It provides control
information based on these inputs.
The M&C has a step-up power supply that is enabled during switch transfers. The supply
gen28VDC at more than 1 amp to control the waveguide switches. After the
switch transfer is complete, the +28VDC supply is shut down. The M&C has a switching
regulator that can ge15VDC at 200 mA to power an external LNA/B. This volt-
age can be enabled or disabled via the remote interface. The M&C monitors the LNA
current and generates a fault if the LNA/B current draw increases or decreases exces-
sively.
The M&C can generate external discrete commands for operation of more than 25W
SSPAs and TWTAs. The M&C also monitors alarm and status outputs from these de-
vices.
The M&C communicates status and control information to the up converter, down con-
verter and 25 W and lower SSPAs via a high speed EIA-485 interface.