SURVEILLANCE FUNCTIONS
SURVEILLANCE FUNCTIONS
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SV-200M Functions
The initial impedance setting is performed by pressing the SET switch on the SV-200M's panel or by external
activation. The speaker lines the SV-200M can cover are those of approximately 1 W to 240 W (100 V line). If initial
setting is not possible (speaker line impedance exceeds the measurable range), an initial setting error is output to
provide short- or open- circuit information depending on the state. However, since whether all 5 output zones are
used differs depending on the project requirements, when an open circuit is detected during initial setting, a
common failure signal is not output, and thus the failure indicator LEDs do not light. When a short circuit is
detected during initial setting, an initial setting error and the same output as was detected in the speaker line
check are provided.
The speaker line check is performed by pressing the CHECK switch on the SV-200M's panel or by activating
from the built-in timer or external equipment. If activated, the speaker line is disconnected from the power
amplifier and is connected to the SV-200M for impedance measurement. If the impedance is approximately
50% lower than that of the initial setting, a short output is provided, and an open output if approximately 200%
higher. If the measurement is completed, the speaker line is reconnected to the power amplifier to restart the
broadcast.
If a shorted speaker line is detected, its zone is disconnected and maintained, while restarting broadcasts to
other zones. The zone is disconnected because broadcasts cannot be made to other zones when even a single
zone fails due to a short circuit. The shorted speaker line is kept disconnected until its status returns to normal.
The time required to check speaker lines of all 5 zones is approximately 20 seconds. During this duration,
background music output and broadcast of Level 3 priority are interrupted. If broadcasts of priority higher than
Level 2 or emergency activation or emergency cutoff states are enabled during the impedance check, the check
will be interrupted and the broadcast initiated.
The built-in timer can be set for 10 - 60 minutes in 10-minute units. To set for shorter or longer intervals than this,
use an external timer.
During broadcasts of a priority higher than Level 2 or during emergency broadcast or emergency cutoff states,
initial setting or impedance checks cannot be activated. However, since the system remembers the activation,
the impedance check will be activated after the broadcast or emergency cutoff state is completed. If Speaker
line ground failure is detected, Initial setting and Impedance check cannot be activated. The initial setting and
impedance check can be activated regardless of the power switch setting.
Since the SV-200M detects speaker line failure by measuring the impedance, it cannot be used in combination
with 3-wire system attenuators. Be sure to use a 4-wire system attenuator when using an external attenuator.
Since speaker line impedance changes due to temperature and time, it is highly recommended that the initial
settings for the speaker lines be re-initialized periodically after checking speaker line operation.
