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Configuring the Amplifier Chassis
PAGASYS GEN II (P-SYS-G)
Federal Signal www.fedsig.com
8.5 Test Features
Test Tone
Use a 20 kHz test tone to check the integrity of the audio system connections. The
System Controller may generate this tone to test the connection from the audio source
to each of the amplifier inputs. The tone may be generated by the amplifier card itself, to
test the impedance of the load speakers. The tone may be generated by the optional ISMT
card.
Impedance Calibration
Use the impedance calibration procedure to capture and store the impedance of speakers
connected to an amplifier card, when ISMT card is not used. Ensure that the system is
not transmitting audio signals prior to initiating the procedure. Initiate impedance testing
on the amplifier from the System Manager in the amplifier Field Diagnostics menu. The
amplifier card generates a test tone and measure its speaker impedance, and then store the
result as a new calibrated value.
NOTE
: Only do calibrations when it has been verified that all speakers are working
without faults and all the tapping adjustment are completed. Any change of the
loudspeaker circuit requires recalibration.
Automatic Testing of Impedance
Each amplifier card periodically tests the impedance of its speakers and compare the
result with the stored calibrated value. All impedance tests are initiated by the System
Controller. If the result is out of tolerance, a load fault is reported on the RS485
communication line and a yellow LOAD FAULT LED turns on.
Earth Fault Detection System
Audio output lines are isolated from earth ground. Earth fault detection system
continuously checks for current leaks, and reports a failure to the System Controller,
when out of tolerance. A LOAD FAULT LED also turns on.
Automatic Monitoring Temperature
Each amplifier card monitors its own temperature and reports to the System Controller.
It turns on its fan when necessary and monitors the fan operation. If the temperature
exceeds 80°C, HIGH TEMPERATURE LED turns on. If the temperature continues to
rise, the amplifier card may shut down.
Cut-out Condition
A cut-out condition, indicated by a yellow CUT OUT LED, means that the Class D
amplifier bridge is disabled. It occurs at every power up, during a normal initial ramp up;
however, a severe overload or other malfunction may extend this condition beyond the
initial ramp up. The condition is reported to the System Controller. The module attempts
to restart the bridge every few seconds.
