Harris ATLAS ANALOGUE, Manual

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7/26/05 888-2523-001 4-15
WARNING: Disconnect primary power prior to servicing.
Section 4 Theory of Operation
ATLAS Analogue
a.
Communicating with the System Controller via the internal Controller Area Net-
work bus
b.
Monitoring the power into the reject power loads from the modules
c.
Monitoring system and cabinet forward RF power
d.
Monitoring cabinet reflected RF power
e.
Maintaining hardware trip points for reject loads and forward and reflected power
sense ports to generate an exception on the transmitter parallel bus in the event of
a fault while in Life Support mode
f.
Calculation of VSWR based on Forward and Reflected power samples (Not
applicable in Life Support mode)
While this board utilizes the micro module, it is basically just responsible for
communicating information from the CPLD to the Main Controller.
4.4.3.1 RF Detectors
There are 2 types of RF detectors used on the RF Controller board:
•
Relative - Used to monitor the reject load power levels. These detectors are
very accurate at a calibrated power level, but are not linear across a wide
dynamic range.
•
Precision - Used for metering of critical (metered) forward and reflected
power levels of the cabinet and the system. These are true RMS detectors
that are linear at all power levels, giving the accurate readings required for
metering and VSWR protection.
Parameters monitored by the RF detectors include:
a. Reject load #1 power
b. Reject load #2 power
c. Reject load #3 power
d. Reject load #4 power
e. Reject load #5 power
f. Reject load #6 power
g. Reject load #7 power
h. Precision RF power measurement #1 Cabinet Forward Power
i. Precision RF power measurement #2 Cabinet Reflected Power