User's Manual Part 1

Table Of Contents
3EM21522AAAA Functiona
l
Description
Issue 1, March 2008 DTR-0200-SA-SIRIUS
2-19
2.4.1
HPA CONTROLLER
The HPA Controller monitors various parameters and reports current values and
summary alarms to the repeater main controller via the RS485 interface. The vari-
ous monitored parameters and statuses are the power modules working conditions
(DC voltages and currents),
the temperature inside the HPA assembly, the HPA for-
ward and reflected power levels, input power and gain, RF power inhibit, HPA power
supply enabled/disabled, input/output overdrive alarm, over-temp alarm (announced
prior to shut-down), over-temp fault, HPA shut-down alarm, output device failure
alarm, driver device failure alarm, HPA low gain alarm, power supply AC fault, and
power supply DC fault.
The HPA Controller also performs HPA pre-driver control, provides the HPA power-
up and shut-down procedure
, and interfaces the HPA to the host (SPU Main Control-
ler). If the HPA controller detects a problem with a specific PA module, it shuts down
the entire HPA. The SPU main controller can restart the HPA utilizing the remain-
ing operational PAs. If the number of faulty PAs exceeds a predetermined threshold,
the HPA can not be restarted by the host.
Since the HPA is a constant gain block, it is individually calibrated to maintain RF
performance under varying operating conditions
. Calibration is performed on the
forward, reflected, and input power sensors. A calibration table dependent on tem-
perature and frequency is stored in the internal EEPROM of the HPA controller.
The HPA controller reports alarms to the main controller and maintains a log of
alarms
. Alarm entries contain the alarm ID and monitored parameters prior to
alarm activation. The alarm log is stored in an internal EEPROM. The HPA control-
ler can enable/disable the output RF and also turn the integrated power supply DC
power ON and OFF.
2.4.2
HPA POWER SUPPLY
The HPA Power Supply is a high performance power source that delivers appropri-
ate voltages and current necessary to operate the HPA at its required performance
level. The power supply resides in a separate compartment inside the HPA module
and employs four independent AC-to-DC converters operating in parallel. The con-
verters’ outputs are combined on a single bus and connect to the input terminal of
the Power Distribution/Controller board located in the power supply compartment.
The Power Supply contains supervisory circuitry to report the status of the AC input
voltage and DC/DC converters operation status to the Power Distribution/Controller
module. This Controller module also monitors the Power Supply DC output voltage
and the current draw of each of the HPA sub-modules, and reports these parameters
back to the Main System Controller via the serial port. In addition, the Power Sup-
ply has the ability to enable/disable the power to the HPA when so commanded by
the Main System Controller.