4.6.3 SUPERVISION OF SPEAKER CONNECTIONS
Every speaker connection is supervised independently. There are two complementary
ways to do it: Measuring line impedance and end of line devices. Using the impedance of the
line, the devices emits a signal periodically every 30 seconds, in a non audible frequency.
Consequently, in a complementary way, to increase the measure of precision of an open
circuit, the end of line devices are used (see 4.6.4), to detect the injected signal, at the end of
the speaker line. If the measure in inside the expected values, a signal is sent to the control
system.
For a correct measure of the speaker connections, the system must be calibrated using
configuration application in the following cases:
• It switches on for the first time.
• Some changes are taking place in the connected speakers, such us:
◦ Some units have been added.
◦ Some units have been reduced.
◦ The adjustment settings of one or various units have been changed.
◦ The model of one or various speakers have been changed.
To disable the measurement of loudspeaker lines or the end of line devices, use the
application configuration.
NOTE: Impedance measurement is not compatible with installed attenuators in the
line, due to they will modify the impedance of the line in a non-lineal way.
4.6.4 END OF LINE DEVICES
The end of line device (also called EOL) provides greater
accuracy in monitoring speaker lines. If no end of line devices are to
be installed, it must be disabled by the configuration application.
EOL devices improve the detection of loudspeaker lines in
open circuit, but can not detect where it has occurred.
The EOL device has two connectors, one for connection to
speaker lines in orange and another one in green for connections to
'End of line inputs' or to another EOL devices.
The connection is made via 2-pin sockets and pitch 5,08 mm
(supplied with the kit). The range of cable sizes for each pole of this connector is: 0,5
2,5mm
2
(22 12 AWG).
36
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