Short-circuit supervision
If line supervision is switched on, the voice alarm controller continuously monitors all
loudspeaker lines in the system for short-circuits.
If a short‑circuit is detected, the line output of the short-circuited line is isolated and shut
down within 200 ms. The system will remain operational. If the line is dual-redundant
connected (A and B), the short-circuited line remains operational as well.
When a ground short occurs, first check the 0 V and 100 V connections from the amplifier to
the Voice Alarm Controller. If these connections are incorrect, then a short fault can occur at
unpredictable times.
Voice alarm controller
VOX configuration
The type of source that is connected to the mic/line input with VOX functionality is set using
the Mic/Line switch on the rear of the voice alarm controller.
– If the source is a microphone, put the switch in the Mic. position.
– If the source is a line-level source, put the switch in the Line position.
Figure 6.3: VOX input source switch
The mic/line input with VOX functionality is configured using DIP switches on the rear of the
voice alarm controller. By default, all switches are in the OFF position.
Figure 6.4: VOX settings
The settings that can be made using the DIP switches are explained in a table on the rear of
the voice alarm controller (see the following table).
Off On
1 VOX activated by mic. VOX activated by VOX switch.
2 Speech filter. Flat.
3 Phantom power Off. Phantom power On.
Table 6.6: Vox settings
The volume of the mic/line input with VOX functionality is set with the VOX volume control.
6.3
6.3.1
Plena Configuration | en 81
Bosch Security Systems B.V. Installation and Operation manual 2013.07 | V2.0 |